Chapter 10: Oncology
Cancer Diagnosis and Registration
- Cancer is unregulated cell division with metastatic potential.
- In general, there are two broad groups of cancers: solid and haematological malignancies.
- Solid malignancies include carcinomas, Melanomas, and sarcomas, which can affect any part of the body. Haematological malignancies include lymphomas, leukemia, and Multiple Myeloma.
- The etiology for cancer is multifactorial: environmental and intrinsic.
- Risk factors include infections, tobacco smoking, age, chemicals, toxins, genetic predisposition, and radiation exposure.
- General cancer prevention strategies need to target risk factors. Cancer screening includes Cervical cancer screening using VIA or pap-smear, Mammography, fecal occult blood with supporting colonoscopy, upper gastro-intestinal endoscopy in high-risk cases for instance those with reflux disease, screening and treatment of premalignant skin lesions in those at risk (e.g. people with Albinism).
- Malawi National Cancer Registry pools data from hospital-based cancer registries, KCH, Zomba and Mzuzu Central Hospitals for epidemiology and surveillance. There is also a population-based cancer registry at QECH.
General Clinical Features
SIGNS AND SYMPTOMS
- Initial presentation depends on the system involved and may include a mass which may or may not be painful and ulcerated.
- GIT tumours may cause difficulties and pain when swallowing, change in bowel habit, abdominal distension.
- Genitourinary tumours: abnormal vaginal discharge and bleeding (spotting, heavy, contact), hematuria.
- Cutaneous malignancies: pigmented skin lesions, limb edema
- Metastatic tumours: back or bone pain, paralysis, fractured limb, headache and seizures.
- Cachexia, recurrent fevers, unexplained weight loss and night sweats may occur with advanced disease or leukemia.
- Cancers involving skin: ulcer with irregular edges, easily bleeds, necrotic.
- For a cancerous mass; it could mobile or fixed, pigmented, exophytic or endophytic with contact bleeding.
- Lymphadenopathy
- Intraabdominal spread may cause palpable mass, ascites, bowel obstruction, jaundice, nodular/irregular hard prostate on DRE.
- Limb involvement causing woody hard edema with or without ulceration, limb swelling due to lymphatic obstruction.
GENERAL INVESTIGATIONS
Laboratory tests:
- Full blood count – persistently elevated or decreased parameters in any of the blood cell lines should raise suspicion of a malignancy.
- Bcr-Abl detected on PCR if Leukaemia suspected.
- Tumour markers -elevated titers of beta-HCG, CEA, AFP, CA-125, PSA, CA 19-9, CA 15-3 and LDH may suggest a particular cancer. Tumour markers may also be used to monitor response to cancer treatment. Caution when interpreting as many are non-specific; need to correlate with the clinical picture and assays used.
- Fecal occult blood.
Radiological tests:
- Mammography and Ultrasound for breast cancer.
- X-rays (Chest/Bone) for detection of primary cancer or metastases.
- Scanning (Ultrasound scan/Computed Tomography/Magnetic Resonance Imaging/Bone Scan/PET-CT) investigating particular sites for cancer involvement and the extent.
Haematology, Cytology, Histology:
- Peripheral blood smear in haematological cancers
- Cytology to assess cancer cells: this examines fluids suspected to be involved with cancer or needle aspirates from cancer masses
- Histology for solid tumors: core biopsy, incision, excision, surgical specimen
- Bone marrow aspirate and trephine biopsy
- Immunohistochemistry: various stains available depending on cancer suspected.
Tests to undertake when specific turmuors are suspected:
- Cervical cancer: punch biopsy for histology.
- Prostate cancer: Transrectal ultrasound guided prostate biopsy (12 core biopsy is the standard; 6 from each lobe) and PSA. Fusion biopsies are not routinely done in the country at the moment.
- HIV test; HIV-related cancers (KS, cervical cancer, lymphoma) are suspected or diagnosed
- Barium swallow, gastroscopy and tissue biopsy for oesophagus or gastric cancer
- Breast cancer: Breast USS, Mammography, biopsy including immunohistochemistry
- Colon cancer: Fecal occult blood, colonoscopy and biopsy
- Lung cancer: Sputum cytology, bronchoscopic, mediastinal or CT-guided biopsy
- Bladder cancer: Cystoscopy, Urine cytology and Trans-urethral resection of bladder tumour with detrusor muscle biopsy represented in the specimen
- Hepatocellular carcinoma: Baseline INR, CT abdomen +/- biopsy, AFP, Hepatitis B and C tests
General Treatment Measures
GENERAL MEASURES
- Treatment for cancers involves a multidisciplinary approach with multiple modalities.
- These include surgery, radiation, laser therapy, systemic therapies (such as chemotherapy, hormonal therapy, immunotherapy and targeted therapy) and palliative care.
- Most of the advanced cancers require all the treatment modalities.
- There is evidence to support better outcomes if cancer cases are managed in specialized centres.
Treatment options depend on:
- Stage of disease at presentation
- Histological type of cancer
- Age of the patient
Factors to consider before each treatment
- Patient's preference
- Availability and cost of treatment as well as expertise on the ground
- Co-morbid conditions (hypertension, DM, COPD, cardiovascular, renal and liver conditions)
- Performance status (general condition of the patient) assessed using WHO, ECOG, Karnofsky scores.
- Age of patient
- Organ function (haematological, liver, renal, cardiorespiratory)