section epub:type=”chapter” id=”c0031″ role=”doc-chapter”> Editor: Jeffrey N. Bryan Veterinary practitioners recognize cancer in feline patients with increasing frequency since, in many countries, improvements in nutrition and preventive health care have led to a growing population of senior cats. Expert guidelines recommend a patient-specific approach to cancer that includes diagnosis, staging, therapeutic intervention, provisions for patient and personnel safety, referral to a specialist where appropriate, and strong client support. This chapter focuses on choosing and administering chemotherapeutic agents, paraneoplastic syndromes, and palliative care. Common types of cancer in the cat are discussed in detail. Cat; feline; cancer staging; biopsy; chemotherapy; personal protective equipment; chlorambucil; cyclophosphamide; lomustine; melphalan; doxorubicin; mitoxantrone; cytosine arabinoside; gemcitabine; methotrexate; 5-fluorouracil; vinblastine; vincristine; vinorelbine; carboplatin; cisplatin; imatinib; toceranib phosphate; mastinib; L-asparaginase; imiquimod; prednisone; prednisolone; lymphoma; injection-site sarcoma; mammary tumor; paraneoplastic syndromes; quality of life; palliative care. Brooke Fowler Veterinary practitioners recognize cancer in feline patients with increasing frequency since, in many countries, improvements in nutrition and preventive health care have led to a growing population of senior cats. Table 31.1 lists common cancers in cats that may be encountered in general practice. Table 31.1 AUS, Abdominal ultrasound; CT, computed tomography; MRI, magnetic resonance imaging. Adapted from: Biller B, Berg J, Garrett L, et al. 2016 AAHA Oncology Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2016;52:181-204. The 2016 American Animal Hospital Oncology Guidelines for Dogs and Cats (available at https://www.aaha.org) recommend a patient-specific approach to cancer that includes diagnosis, staging, therapeutic intervention, provisions for patient and personnel safety, referral to a specialist where appropriate, and strong client support.1 This section focuses on diagnostics and staging. Once neoplasia is suspected, the diagnosis must be confirmed. The most commonly used tool for diagnosis is a biopsy. The advantages and disadvantages of each method are found in Table 31.2. In some cases, other tests must be used to confirm or clarify a diagnosis, such as immunohistochemistry, proliferation markers, tissue stains, polymerase chain reaction for antigen receptor rearrangement (PARR), and flow cytometry. Table 31.2 Most palpable masses can be sampled with a needle. Fine-needle sampling is the least invasive diagnostic approach that still offers high yield to define the malignancy, especially when the lesion is firm. Cytologic diagnosis often depends on the type of tumor. Round and epithelial cells may exfoliate more completely than tumors of mesenchymal origin. The smallest needle necessary should be used to safely and adequately collect cells for diagnosis. Needles of 22- to 25-gauge are typically sufficient, even for masses present in bone. There are two ways to perform fine-needle sampling. The first method is a non-aspiration technique using a needle without an attached syringe or with a syringe containing 4–6 mL of air. In an oscillating motion, the clinician inserts the needle into the lesion multiple times to collect sufficient cells for a smear. Using 4–6 mL of air, the clinician forcefully expels the contents of the needle onto a slide. The expelled material is gently spread on a blank slide to create a monolayer of cells. One slide is stained to ensure that cells were obtained and adequately prepared. The rest of the sample is sent unstained to a clinical pathologist. The second technique involves placing the needle into the lesion and aspirating with a syringe. The clinician removes the needle, fills the syringe with air, reattaches the needle, and then forcefully expels the contents of the needle onto a slide and prepares as previously described. If surgical biopsies are submitted as well, cytology slides should always be packaged separately from formalin containers. Occasionally, as in the cases of carcinomatosis, sarcomatosis, mesothelioma, and some other tumors, there is no discernable mass to aspirate. Diffuse diseases that present with pleural or peritoneal effusion often can be diagnosed via fluid aspiration and analysis. In people, sensitivity, specificity, and accuracy can be very high in diagnosing neoplasia versus other diseases using fluid analysis. However, in people, other cytochemical, flow cytometric, and fluid chemistry markers are typically assessed in conjunction with these tests.2 In veterinary medicine, there are no known markers for separating inflammatory disorders from neoplasia. Often, the cytology is difficult to interpret since inflammation in the pleural or peritoneal lining can cause significant dysplastic changes, and neoplasia can cause secondary inflammation. This “chicken or the egg” conundrum can make interpretation of these samples difficult. Histopathology is often used when cytology cannot facilitate a diagnosis as it provides information on cellular differentiation, tissue architecture, and tumor grade. Proper technique is important to obtain an adequate sample and prevent seeding of the cancer into adjacent tissues. Basic principles of biopsies for histopathology are found in Box 31.1. Biopsy samples should be collected along the periphery of a lesion, as a rule. This ensures that the necrotic center of a mass will not be sampled instead of the viable portion. This also facilitates skin closure as neoplastic tissue has poor healing capabilities. The one exception to this rule is a tumor of bone. When a biopsy of bone tumors is performed, the samples should include the center of the lesion. Aspirates or biopsies performed at the periphery of a bone lesion will likely yield reactive bone. A needle-core biopsy (e.g., TruCut) performed with imaging guidance is most suitable for sampling internal organ lesions. Needle-core biopsy techniques (e.g., Jamshidi) are also used for bone samples. When using a TruCut device, the core is inserted into the tissue mass. The sheath of the needle biopsy device is then advanced, and a portion of tissue is cut free within the notch of the core. Multiple specimens should be collected. Automatic firing devices can speed the collection of each sample. However, these automated, spring-loaded devices can be too vigorous for internal organs, causing organ damage in smaller patients.3 Removing a small but representative sample of the tumor facilitates identification of tissue architecture, allowing the pathologist to make a diagnosis and identify potential lymphatic or vascular invasion. A wedge of tissue is excised with a scalpel blade along the edges of the lesion. The wedge should have the smallest side along the center of the lesion and the longest side along the lateral margins. Care should be taken not to extend the incision into normal tissue that could not easily be excised with the tumor. This procedure carries some risk of spreading the tumor within normal tissue and requires careful planning to keep cells and hemorrhage contained within the ideal excisional surgical field. A punch biopsy is most suitable for skin lesions. When a biopsy punch is used, cutaneous and subcutaneous samples can be acquired transdermally or through a small skin incision. The biopsy punch is rotated, always in the same direction, into the lesion to the desired depth within the mass. With Metzenbaum scissors, the sample is cut away from adherent underlying tissues. The sample is placed in formalin at a ratio of 1-part tissue to 10-parts formalin and submitted to a pathologist, who will provide a complete microscopic description, diagnosis, grade, margin description, and mitotic index as indicated. Complete excision of the tumor, when possible, can be at once diagnostic and therapeutic. However, failure of complete excision functionally spreads the tumor farther inside the patient, potentially worsening the prognosis.4 Excision of a mass should be attempted only with careful prior planning to ensure a complete excision. Lateral margins must be at least 2 to 3 cm wide, and in the case of injection-site sarcomas, 5 cm all around, and one complete fascial plane must be resected deep to the mass for the excision to be considered complete. Given the small size of the feline patient, this may not be feasible. Such margins can be particularly difficult to achieve with injection-site sarcomas, making preoperative imaging necessary for surgical planning. If complete excision is not considered highly likely, the veterinarian should consider an incisional biopsy for diagnosis before a major surgical procedure. Other molecular tests are emerging for confirming the presence of monoclonal populations of round cells in either tissue samples or blood samples. These tests are constantly evolving and can be used to confirm the presence of neoplasia as well as provide immunophenotype and prognostic information. When lymphoma is suspected, PARR can be used on cytology samples. This test can utilize slides that have already been stained for analysis, so secondary sampling to obtain more cells is often not required. This test can be performed to assess the clonality and immunophenotype of the cells to distinguish lymphoma from inflammatory lymphoid cells. Lymphocyte diversity is generated by random recombination of gene segments of the variable, diversity, and joining segments. These random segments make up the variable regions of lymphocyte receptors responsible for recognizing antigens. Lymphoma is characterized by a monoclonal expansion of malignant lymphoid cells whereas inflammatory lymphoid cells are typically polyclonal. In one prospective study, sensitivity of PARR for diagnosis of lymphoma in cats was 70% with 90% specificity, 77% accuracy, 93% positive predictive value, and 60% negative predictive value.5 Flow cytometry can be used to diagnose lymphoproliferative disorders in cats by evaluating clonality and molecular expression. Since morphology is not necessarily indicative of immunophenotype, flow cytometry can aid in diagnosis. Flow cytometry can confirm a diagnosis of lymphoma and assess immunophenotype.6 A variety of markers are available for feline lymphoproliferative disorders. Sensitivity and specificity have not been assessed since this is an interpretative test. Fine-needle sampling or blood collection can be performed to obtain cells for analysis. The test requires live cells in order to properly evaluate markers and clonality. When cells are collected by fine-needle sampling, they are put into a special media or 1 mL of saline in combination with 0.1 mL of feline serum for laboratory submission. Staging is the process of determining the extent of local disease and whether regional or distant metastasis exists. The extent of the diagnostics depends on the individual tumor type as well as the individual patient and owner. Staging helps determine the best treatment approach and the prognosis. For example, evidence of distant metastasis generally implies a poorer prognosis, often suggests that chemotherapy is indicated, and may affect the owner’s decisions. A commonly used system in veterinary medicine devised by the World Health Organization is called Tumor-Node-Metastasis (TNM).7 It is based on the extent of the primary tumor, status of regional lymph nodes, and whether distant metastasis is present (Table 31.3). Certain types of cancers have their own staging system. These systems may include factors such as the presence or absence of clinical signs (e.g., lymphoma), the degree of malignancy (e.g., mast cell tumors), or the tumor site (e.g., squamous cell carcinoma). Table 31.3 A thorough physical examination and minimum database (complete blood count [CBC], serum chemistry panel, urinalysis) is the first step. A CBC can reveal hematologic malignancies and bone marrow–infiltrating diseases. The CBC may reveal evidence of chronic inflammation including anemia, hyperproteinemia due to hyperglobulinemia, and/or an inflammatory leukogram. The CBC is also a way to primitively assess the innate immune system’s cell constituents. Serum biochemistry data aid in the evaluation of general organ function as well as screening for hepatic lipidosis, the most common secondary disease.8 General body cavity imaging is necessary because not all malignancies lead to biochemical alterations. Complete staging includes both abdominal and thoracic radiographs, and potentially abdominal ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI). Each cancer type has its own predilection for sites of metastasis, and therefore complete staging is tailored to individual cancer type. However, general assumptions can be made. By knowing the cell type of origin, the veterinarian can predict the route by which cancer most likely will metastasize. Round cell tumors tend to metastasize by way of the lymphatics. Therefore, cytologic examination of the draining lymph nodes surrounding round cell tumors is part of a thorough cancer workup. Mesenchymal cell tumors tend to metastasize hematogenously. Therefore, thoracic radiographs are always indicated. Lastly, epithelial tumors tend to metastasize by way of either lymphatics or blood. Lymph node imaging and aspiration, as well as thoracic radiographs, are warranted to assess the metastatic status of a patient with a carcinoma. Aberrant metastatic patterns can suggest aggressive behavior. Sarcomas spreading by lymphatics or round cell tumors metastatic to pulmonary parenchyma may suggest a worse-than-typical prognosis for that patient. Imaging such as CT scans and MRI can be used to diagnose disease in closed cavities (e.g., skull, spine, abdominal, and thoracic cavities). Information from CT and MRI scans can be used to improve surgical planning. Another commonly used diagnostic modality is nuclear scintigraphy. Radioactive isotopes can be tagged to target specific body tissues. These radioisotopes can be used to locate bony lysis or even to elucidate the biological activity of a thyroid mass. Jenna H. Burton Chemotherapy is a mainstay of cancer treatment in cats and is most effective when treating tumors of minimal bulk with an increased rate of cell division. Some cancers, such as lymphoid neoplasms, are treated primarily with chemotherapy. For other tumor types, chemotherapy may be used in an adjuvant setting after local surgery and/or radiation therapy. Occasionally, chemotherapy is used when there is advanced, metastatic cancer to slow the rate of tumor progression and palliate clinical signs; monitoring and awareness of the cat’s quality of life is of paramount importance in this situation. Treating cats with chemotherapy is no more technically challenging than many other commonly performed veterinary procedures. However, the decision to administer chemotherapy must include an assessment of risk to staff and cats that is unique to this treatment modality, as well as the financial aspects and practicalities of safely storing, preparing, and administering chemotherapeutic agents. Treating cancer in cats is similar to managing any chronic disease in this species; the veterinarian’s goals should be to treat the underlying disease while maintaining or improving the pet’s quality of life throughout the course of therapy. To ensure that chemotherapy is both safe and appropriate for the cat, an accurate cytologic or histologic diagnosis must be reached, and any concurrent health problems must be identified to assess the risk of toxicity to the individual cat. Staging tests, such as complete blood count (CBC), serum chemistry profile, urinalysis, thoracic radiographs, abdominal ultrasound, computed tomography scan, magnetic resonance imaging, and bone marrow aspirate cytology, may be needed to determine if the cancer is localized to one area or if it has metastasized. Advanced-stage cancers generally carry a poorer prognosis and increased risk of toxicosis secondary to treatment, which may alter the owner’s willingness to pursue therapy. To make a well-informed decision regarding treatment of a pet, the owner should understand the expected prognosis as well as the possible risks, cost, and time commitment associated with therapy. The aim of this section is to provide practitioners with information regarding the safe handling and administration of chemotherapy as well as information regarding dosing and potential toxicoses of some of the chemotherapy agents commonly administered to cats. Additional resources are found in Box 31.2. The risk of exposure of personnel to chemotherapy drugs is greatest during preparation and administration. These cytotoxic drugs may have mutagenic and carcinogenic effects. All staff members should be aware of the risks of exposure to these drugs and follow protocols to minimize the risk. Clinics that administer chemotherapy should have a written set of guidelines for the safe handling of cytotoxic drugs and plans for managing chemotherapy spills or other exposures.1,2 Some states now require adherence to the USP (United States Pharmacopeia) General Chapter 800 guidelines (Box 31.2); veterinarians are responsible for knowing the regulations in their state. Areas used for chemotherapy preparation and administration in the hospital should be clearly identified, and traffic through those areas should be limited. Storage or consumption of food and beverages, including gum chewing, should be prohibited in these areas to prevent accidental drug ingestion. Cytotoxic drugs should be stored separately from other medications and their location clearly labelled. Facilities that prepare injectable chemotherapy agents should have a class II biologic safety cabinet vented to the outside that is located in a clutter-free space designated for chemotherapy preparation. The work surface should be covered with an absorbent pad with a nonporous backing to help contain any spills that may occur. Items required for preparation of antineoplastic drugs are listed in Box 31.3. Personal protective equipment (PPE), including gloves, gown, protective eyewear, shoe covers, and a respirator or heavy-duty mask, should be worn when preparing cytotoxic drugs. Gowns should be made of a low-permeability fabric and have a closed front and long sleeves with elastic cuffs. Chemotherapy gloves or two pairs of latex, nitrile, or neoprene powder-free gloves are recommended, and gloves should be worn over the cuffs of the gown. A chemotherapy spill kit should be easily accessible in all areas where chemotherapy is handled. Box 31.4 lists the items necessary for a chemotherapy spill kit; alternatively, ready-made spill kits can be purchased. Reconstitution of chemotherapy drugs may cause aerosolization of the agent and devices designed to prevent this must be used. A closed-system drug delivery device should be used (Box 31.5). Closed-system transfer devices prevent aerosolization of drugs and provide a leak-free (dry) connection between the vial, syringe, infusion set, and the cat; they have been demonstrated to decrease surface contamination and personnel exposure.3,4 Use of a closed-system transfer device does not increase time of administration of chemotherapy to the patient as compared to chemotherapy administration without a closed-system device.5 Regardless of the delivery device used, the use of Luer-lock syringes is essential when reconstituting or drawing up chemotherapy drugs to prevent accidental disconnection of the syringe from the delivery system. For chemotherapy agents administered diluted in saline, Y-port closed-system adaptors can be utilized to administer the drug along with the saline by gravity drip infusion. Alternatively, if the agent is added to the bag of saline for dilution, intravenous (IV) fluid lines should be primed before the addition of the chemotherapy agent to the infusion bag to prevent contamination when priming the line. Once chemotherapy preparation is complete, the drug should be placed in a sealable plastic bag for transport to contain any leaks or spills that may occur during transportation. Suppliers of chemotherapy equipment are listed in Box 31.5. All materials that have been in contact with chemotherapy agents during preparation and administration should be disposed of in a designated chemotherapy waste container. This includes gloves, gowns, absorbent pads, catheter materials, syringes, fluid bags, and IV lines that that have been used for chemotherapy administration. Sharps should be disposed of in a designated chemotherapy sharps container. Regulations regarding proper disposal of hazardous waste vary among municipalities; local and state officials should be consulted to ensure that disposal meets with Environmental Protection Agency standards in the United States and with the standards of the respective authorities in other countries. Obtaining a thorough history at each visit will help the practitioner identify any toxicoses experienced by the cat after prior chemotherapy treatment, guiding treatment delays and dose reductions if the cat’s quality of life has been adversely affected by treatment. At each appointment, cats should have their body weight, body condition, muscle condition, temperature, heart rate, and respiratory rate recorded and receive a complete physical examination. A CBC should be performed before each dose of chemotherapy. A biochemical panel should be performed as needed depending on the toxicity profile of the drug to be administered. Cats that appear to be feeling unwell at the time of the chemotherapy appointment should not be administered chemotherapy that day, and appropriate diagnostic tests should be performed to identify any new problems or complications from therapy. If the cat is determined to be ill secondary to its cancer, decisions regarding treatment need to be weighed based on the likelihood that a remission can be achieved with treatment and whether chemotherapy will potentially improve quality of life or further impair it. The cat’s chemotherapy dose should be calculated from the body weight obtained at that visit. The clinician should pay particular attention to whether the drug is to be dosed on the basis of body weight (kilograms) or body surface area (m2). A chart converting body weight into body surface area should be easily accessible when calculating the chemotherapy dose. A system in which a second person double-checks drug type, dosage, and calculation of dose is critical to prevent dosing errors. When recording doses of chemotherapy to be administered, avoid using trailing zeros to prevent miscommunication and accidental overdose. For example, two milligrams should be written as “2 mg” rather than “2.0 mg” to ensure that the latter is not misread as “20.” Prior to administration, the cat’s name, drug type, and drug dose should be double-checked against the drug label, patient chart, and patient identification tag or collar. Results of the CBC and other bloodwork should be reviewed to verify that cell counts and other parameters being monitored are adequate to proceed with treatment. Additionally, a record documenting the drug given, dosage, dose, and route administered, vein used for chemotherapy administration, initials of person administering the drug, and any adverse reactions should be maintained in the cat’s medical record. Standard operating procedures should be developed, and personnel instructed regarding the proper handling and disposal of waste from chemotherapy patients. Owners should be given written instructions regarding these as well. Depending on the drug administered, urine, feces, saliva, and vomitus may contain small amounts of chemotherapy agents and their metabolites for as long as 5 days after administration; chemotherapy drugs that undergo substantial protein binding may not be fully excreted for more than 21 days after treatment.6,7 While the cat is in the hospital, cage cards identifying chemotherapy patients should be used to alert staff members responsible for cleaning soiled cages. Soiled linens should be washed separately, and disposable gloves should be worn when cleaning up urine, feces, or vomitus during this time. Litter boxes should be changed daily for several days after treatment and use of litter box liners or disposable litter boxes may help prevent aerosolizing chemotherapy metabolites. Cats undergoing treatment that reside in multicat households do not need to be isolated from other pets; there is no reported risk associated with sharing litter boxes or food dishes at this time. Oral antineoplastic drugs are commonly used in veterinary oncology. Although these are often perceived by pet owners to be safer and easier to administer than IV agents, clients must be counseled regarding the proper handling of these medications. Tablets should never be split or crushed, and capsules should not be opened; doing so may lead to the exposure of the owner through inhalation, skin contact, or ingestion. Similarly, chemotherapy drugs should not be compounded into liquid formulations. Owners should be given disposable, powder-free gloves to wear when handling oral chemotherapy agents, and hands should be washed after administration. Cats should be encouraged to eat a small amount of food or carefully given several milliliters of water by mouth with a syringe after administration of the drug to ensure passage of the tablet or capsule into the stomach. Some owners will request that the oral chemotherapy agent be administered while the pet is at the hospital. This can be problematic if the cat is prone to motion sickness and vomits the medication during the car ride home. If the owner is capable, administration of the drug once the pet is at home is preferable. It is recommended that the jugular veins be used for blood collection and peripheral veins preserved for chemotherapy administration. If a peripheral vein is used for venipuncture, it should be bandaged or otherwise identified to avoid administration in this vein. An atraumatically placed indwelling IV catheter should be used for administration of chemotherapy volumes greater than several milliliters. This step is of critical importance for the patient as many chemotherapy drugs are potent vesicants. If the catheter is not placed cleanly on the first attempt, the catheter should be removed and placed in a different peripheral vein. Sedation should be considered for difficult cats to ensure that the IV catheter remains in place throughout the chemotherapy infusion. Similarly, vascular access ports may be helpful for repeated administration of chemotherapy to difficult cats. The catheter insertion site should not be covered to allow monitoring for evidence of extravasation during administration. Cats that are being treated with known vesicant drugs should not be placed in cages during passive drip infusions but should be actively monitored throughout the infusion to ensure patient safety. Fig. 31.1 lists the equipment necessary for IV administration of cytotoxic drugs. Personal protective equipment, as previously described, should be worn by the individual administering the drug and any personnel involved in restraint of the cat. An absorbent pad with a plastic backing should be placed underneath the limb used to deliver the drug. A butterfly catheter can be used for cooperative cats receiving small chemotherapy volumes (<1 to 2 mL). For larger volumes or longer infusions, an indwelling catheter should be placed. To ensure catheter patency, the catheter should be flushed thoroughly with nonheparinized saline and aspirated to assess adequate blood return before administration. Chemotherapy agents that are known vesicants should not be infused with an IV fluid pump. Chemotherapy drugs should be administered by manual syringe infusion or slow gravity drip with active patient monitoring over the recommended time of administration. For agents that are administered diluted in saline, Y-port closed-system adaptors can be utilized for administration of the drug. Alternatively, if the chemotherapy drug has been diluted directly in the fluid bag, the bag should be lowered beneath the cat every few minutes to ensure there is backflow of blood and the catheter remains patent. If the drug is administered through a syringe, the plunger should be aspirated back several times during administration of the drug to ensure that blood still appears in the hub of the catheter. The catheter site should be monitored throughout administration; if swelling at the catheter site is observed during the infusion, administration should be discontinued, and extravasation protocols initiated. Once the chemotherapy infusion is complete, the catheter should be flushed again with nonheparinized saline before removal. A light bandage should be placed over the catheter site after removal.
Oncology
Abstract
Keywords
Basic Approach to the Feline Cancer Patient
INTRODUCTION
Tumor type
Common locations
Behavior
Staging tests
Lymphoma
Thymus, gastrointestinal, liver, spleen, kidney
Considered a systemic disease except for nasal lymphoma which is localized, some forms are indolent and slow to progress.
Three-view chest radiographs, AUS, CT/MRI if CNS involvement, immunophenotype less critical for the cat than the dog.
Mammary gland carcinoma
Mammary gland
Locally aggressive, highly metastatic to lymph nodes, liver, lungs.
Three-view chest radiographs, AUS, regional lymph node sampling, CT/MRI for surgical or radiation therapy planning.
Squamous cell carcinoma
Oral, cutaneous (nasal planum, pinnae, multifocal in situ)
Locally aggressive especially oral, low metastatic rate, cutaneous forms often slowly progressive.
Three-view chest or skull/oral radiographs, CT scan, regional lymph node sampling.
Soft tissue sarcomas (including injection-site sarcoma)
Cutaneous, subcutaneous tissues; injection sites
Injection-site is locally aggressive with high local recurrence; other sites are less aggressive, location- and grade-dependent; high metastatic rate for high grade and/or injection-site; low metastatic rate for low grade, non–injection-site
Three-view chest radiographs, CT/MRI for surgical/radiation planning, AUS
DIAGNOSIS OF TUMOR TYPE
Method
Advantages
Disadvantages
Fine-needle
Minimally invasive and affordable, rarely requires sedation or anesthesia, diagnosis may be rapid, can be used for skin, bone, internal organs. Best for round and epithelial cell tumors.
Small sample size may not be representative of the tumor population, results may be nondiagnostic and delay diagnosis.
Needle-core
Minimal surgical site closure (less risk of dehiscence or infection compared to surgery), tumor architecture and grade may be determined, immunohistochemical stains and other tests possible.
Sedation with local anesthesia or general anesthesia often required, nondiagnostic sample if crush artefact is present, risk of internal organ damage or hemorrhage with automated devices.
Incisional (wedge, punch)
Large samples are obtained, tumor architecture and grade may be determined, immunohistochemical stains and other tests possible.
Sedation with local anesthesia or general anesthesia required, risk of site dehiscence, risk of tumor spread to normal tissue.
Excisional
Potentially curative, large samples are obtained, tumor architecture and grade may be determined, immunohistochemical stains and other tests possible.
Most invasive technique, general anesthesia required.
Biopsy Techniques
Fine-Needle Sampling and Cytology
Tissue Biopsy and Histopathology
NEEDLE-CORE BIOPSY
INCISIONAL BIOPSY
EXCISIONAL BIOPSY
Additional Tests
CANCER STAGING
PRIMARY TUMOR (T)
Tis
Preinvasive tumor (carcinoma in situ)
T0
No evidence of primary tumor
T1
T2
T3
REGIONAL LYMPH NODES (N): CERVICAL, SUBMANDIBULAR, PAROTID
N0
No regional lymph node involvement
N1
N2
N3
Fixed lymph nodes
DISTANT METASTASIS (M)
M0
No evidence of distant metastasis
M1
Distant metastasis is present
STAGE GROUPS
I
TI; N0, N1A or N2A; M0
II
T2; N0, N1A or N2A; M0
IIIa
IV
For the References and other additional features, please visit eBooks.Health.Elsevier.com.
CHEMOTHERAPY FOR THE FELINE CANCER PATIENT
INTRODUCTION
CHEMOTHERAPY PREPARATION
CHEMOTHERAPY DOSING AND ADMINISTRATION
Oral Administration
Intravenous Administration
. A Mayo stand covered with ChemoSorb pad is set up for chemotherapy administration for a patient using the PhaSeal delivery system. (A) Items for catheter placement including 2 × 2 gauze squares to aseptically prepare the IV catheter site, appropriately sized catheter for the patient, tape for securing the catheter, and bandage scissors. (B) T-port with syringe of nonheparinized saline attached. (C) PhaSeal connector that attaches to the T-port for drug administration. (D) Syringe of nonheparinized saline with PhaSeal injector attached. (E) Chemotherapy drug for the patient in a Luer-lock syringe attached to a PhaSeal injector and contained in a chemotherapy bag (note that both the syringe and bag are labelled with the patient’s name as well as drug name, concentration, and volume to be administered). (F) Bandaging material for when the IV catheter is removed after administration. Not shown: personal protective equipment, including gowns, gloves, and eye protection.
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