Oncology - Overview

Head and Neck Cancer

• Malignant tumors arise in the head and neck region, affecting areas like the tongue, oral cavity, pharynx, and larynx.
• Causes include smoking, alcohol consumption, and HPV, particularly in oropharyngeal cancers.
• Poor diet and environmental exposures are possible contributing factors.
• Treatment involves a multidisciplinary approach including surgery, radiotherapy, and chemotherapy.
• Radiotherapy is used post-operatively (adjuvant) or pre-operatively (neoadjuvant).
• Dental assessment is important before radiotherapy.
• Prevention includes avoiding smoking, limiting alcohol intake, and maintaining good oral hygiene.
• HPV vaccination in younger populations can reduce the risk of oropharyngeal cancer.

Cancer (Generic)

• A group of diseases with abnormal, uncontrolled cell growth, potential local invasion, and possible metastasis.
• Causes are multi-factorial, involving genetic abnormalities and risk factors like smoking, alcohol, diet, and viruses.
• Treatment includes surgery, radiotherapy, chemotherapy, and hormone therapy, depending on the cancer type.
• Staging (TNM) and grading guide the therapy plan.
• Prevention involves minimizing modifiable risk factors like smoking, excessive drinking, and obesity.
• Screenings are available for certain cancers, such as cervical smears and mammograms.

Breast Cancer

• Malignancy arising from breast tissue.
• Hormonal factors such as prolonged estrogen exposure and HRT, genetics (BRCA mutations), and environmental factors are causes.
• Treatment includes surgery (lumpectomy/mastectomy), radiotherapy, chemotherapy, and hormone therapy (e.g., tamoxifen).
• Prevention includes limiting HRT usage if possible, regular screenings (mammograms), and maintaining a healthy lifestyle.

Liver Disease / Liver Cancer

• Chronic liver inflammation may lead to cirrhosis or hepatocellular carcinoma.
• Viral infections, specifically Hepatitis B and C, are the causes.
• Treatment includes antiviral therapy for hepatitis B/C, supportive care, and liver transplantation in advanced cases.
• Prevention includes vaccination for Hepatitis B, avoiding IV drug use/contaminated needles, and practicing safe sex.

Cervical Cancer

• Malignancy in the cervix, often linked to human papillomavirus (HPV).
• High-risk HPV subtypes such as HPV-16 and -18 are the primary causes, while smoking and immunosuppression can be co-factors.
• Treatment includes surgery (cone biopsy or hysterectomy), radiotherapy, and chemotherapy if advanced.
• Prevention includes HPV vaccination, cervical screening through Pap tests, and safe sex practices.

Oropharyngeal Cancer

• Cancer of the oropharynx, especially in the tonsils and base of the tongue.
• HPV infection, especially HPV-16, smoking, and alcohol are causes.
• Treatment includes surgery, radiotherapy, and possibly chemotherapy.
• Prevention involves HPV vaccination, reducing tobacco use, and limiting alcohol intake.

Nasopharyngeal Cancer

• Malignancy in the nasopharynx strongly linked to the Epstein-Barr Virus (EBV).
• Causes include EBV infection, specific diets high in salted fish (in some regions), and genetic susceptibility.
• Radiotherapy is a key treatment; chemotherapy is often used for advanced disease.
• Prevention strategies aren't well established, except for avoiding certain dietary risk factors; controlling EBV spread is difficult.

Burkitt’s Lymphoma

• High-grade B-cell Non-Hodgkin’s lymphoma.
• Has a strong association with EBV and immunosuppression.
• Treatment consists of intensive chemotherapy regimens.
• Prevention is not specifically achieved by vaccine yet; controlling immunosuppression and EBV awareness are important.

Pancreatic Cancer

• Malignancy of the pancreas, often discovered late because of vague symptoms.
• Smoking, chronic pancreatitis, family history, and a possible diabetes link are causes.
• Treatment includes surgery (Whipple procedure) if resectable, with chemotherapy/radiotherapy used palliatively.
• Prevention involves avoiding smoking, managing weight, but early detection is challenging.

Ovarian Cancer

• Malignancy of the ovaries, typically presents late with abdominal distension/bloating.
• Genetic predisposition (BRCA), age, and obesity are causes.
• Treatment involves surgery (oophorectomy, hysterectomy) and chemotherapy.
• Prevention includes genetic counseling for BRCA and oral contraceptives, which may reduce some risk.

Antrum Cancer

• A stomach cancer located in the antrum region that can silently expand.
• Helicobacter pylori infection, smoking, and a diet high in nitrates are causes.
• Treatment consists of surgical resection (gastrectomy), chemotherapy, and radiotherapy in some cases.
• Prevention includes H. pylori eradication, a healthy diet, and avoiding smoking.

Leukemia

• Cancer of white blood cells, leading to abnormal leukocyte proliferation.
• Causes include various genetic or environmental factors; certain chemicals/radiation might increase risk.
• Treatment includes chemotherapy and possibly a stem cell transplant.
• No specific prevention exists, except for limiting radiation exposure/chemicals.

Lymphoma

• Malignancy arising from the lymphatic system; includes Hodgkin or Non-Hodgkin lymphoma and Burkitt’s lymphoma.
• Linked with EBV (like Burkitt’s), immunosuppression, and genetics.
• Treatment includes chemotherapy, radiotherapy, and immunotherapy.
• No specific measures exist, except for limiting immunosuppression if possible.

Squamous Cell Carcinoma

• A carcinoma arising from squamous epithelial cells, found in the oral cavity, oropharynx, and skin.
• Causes include tobacco, alcohol, and HPV involvement.
• Treatment includes surgery, radiotherapy, and chemo, depending on the site and stage.
• Prevention involves avoiding risk factors such as smoking, alcohol, and UV exposure for skin SCC.

Sarcoma

• Malignancy of connective tissue, including bone, muscle, and cartilage.
• Often sporadic, but some genetic predispositions or radiation history can be causes.
• Treatment includes surgery and radiotherapy, with chemotherapy for some subtypes such as osteosarcoma.
• Not typically preventable; early detection is key.

Basal Cell Carcinoma

• Malignancy arising from the basal layer of epithelia, often seen in the skin.
• UV exposure is the main risk factor for skin BCC.
• Surgical excision, Mohs micrographic surgery, and topical therapies in superficial cases are treatments.
• Limit sun exposure and use sunscreen for prevention.

Adenocarcinoma

• A carcinoma arising from mucus-producing glandular epithelium, found in the colon, lungs, and breast.
• Causes include smoking (for lung adenocarcinoma), genetics, and diet.
• Treatment includes surgery if localized, plus chemo/radio as indicated.
• Prevention depends on the site such as colonoscopy for colon adenocarcinoma and avoiding smoking for lung cancer.

Oral Mucositis

• An inflammatory/ulcerative condition of the oral mucosa, featuring erythema, pain, and ulceration.
• A common side effect of both radiotherapy and chemotherapy.

Hyposalivation / Dry Mouth (Xerostomia)

• Reduced salivary flow leads to dryness of oral tissues.
• Radiotherapy, particularly when major salivary glands are in the field, can permanently reduce their function.

Infections (Candidal / Herpetic / Sialadenitis)

• There is increased susceptibility to oral infections such as fungal (Candida), viral (Herpes simplex/zoster), or bacterial inflammation of salivary glands (sialadenitis).
• Caused by immunosuppression from chemo and dryness from radiotherapy.

Hypogeusia (Taste Loss)

• Partial or complete reduction in the sense of taste.
• Often occurs due to damage to taste buds or salivary changes from radiotherapy.
• Recovery can take months or not occur at all if the dose is very high.

Radiation Caries

• Rapidly progressing caries affects cervical/smooth surfaces due to xerostomia and changes in oral flora.
• Results from lack of protective salivary flow and buffering.

Trismus

• Reduced mouth opening caused by fibrosis in the masticatory muscles or TMJ area.
• Radiation‐induced fibrosis or scarring occurs around jaw muscles.

Osteoradionecrosis (ORN)

• An area of necrotic, exposed bone in irradiated bone that fails to heal over months.
• Due to endarteritis obliterans (narrowed vessels), leading to poor blood supply, hypo‐vascular and hypo‐cellular bone.

Methotrexate

• Anti‐metabolite chemotherapy (also used in rheumatology); inhibits folate metabolism
• Cell‐cycle specific (phase‐dependent).
• Can cause oral mucositis.
• Folic acid or Folinic acid sometimes helps reduce toxicity.

Vinca Alkaloids (e.g., vincristine)

• Anti‐mitotic chemotherapy that stops cell division by interfering with microtubules.
• Cell-cycle specific (phase-dependent).

5‐FU (5‐Fluorouracil)

• Anti‐metabolite chemo drug that inhibits DNA synthesis
• Cell-cycle specific (phase-dependent).
• Often used for GI cancers, among others.

Alkylating Agents (e.g., cyclophosphamide)

• Chemotherapy class that damages DNA.
• Non‐phase-dependent.
• Risk of long‐term carcinogenesis.

Antimitotic Antibiotics (e.g., bleomycin, dactinomycin)

• Chemotherapy agents that disrupt cell replication.

Interferon / Monoclonal Antibodies (e.g., alpha interferon, various “‐mab”)

• Immunomodulatory or targeted therapies in certain cancers.
• Improves immune response or targets tumour pathways.

Folinic Acid (“Leucovorin”)

• "Rescue” agent in high‐dose methotrexate regimens.
• Helps mitigate methotrexate‐induced ulceration.

Nystatin / Miconazole

• Topical antifungals for Candida infections.
• Commonly used in immunosuppressed or dry mouth patients.

Fluconazole

• Systemic antifungal for candidiasis or other fungal infections.
• Especially useful if topical therapy fails.

Acyclovir

• Antiviral agent for herpetic infections (HSV, VZV).
• Herpetic infections can flare up in immunosuppressed cancer patients

Benzydamine Hydrochloride (Difflam)

• Topical NSAID rinse/spray used to manage oral mucositis pain and inflammation.

Suxamethonium (Scoline)

• A depolarizing muscle relaxant used typically for rapid sequence induction (general anaesthesia).
• Toxicity may increase in those on methotrexate.

Aspirin

• Specifically contraindicated with methotrexate due to toxicity concerns.

Benzydamine Mouthwash (Difflam®)

• Topical NSAID rinse to alleviate pain/inflammation in oral mucositis caused by radiotherapy/chemotherapy.
• Locally reduces prostaglandin-mediated inflammation and pain in the oral mucosa.

Low-Level Laser Therapy

• Used for managing oral mucositis in head and neck cancer patients undergoing radiotherapy/chemotherapy.
• Non-thermal laser light promotes mucosal healing and reduces pain/inflammatory mediators.

Brachytherapy

• Internal radiotherapy for prostate or certain head and neck tumours.
• Radioactive sources are placed close to or inside the tumour to deliver high local radiation with limited exposure to surrounding tissues.

Fractionation (in Radiotherapy)

• Key principle in external-beam radiotherapy to deliver the total prescribed radiation dose in multiple, smaller sessions.
• Spreads out radiation delivery, allowing normal tissues to repair between fractions while maximally damaging rapidly dividing tumour cells.

Scalp Cooling

• Minimizes hair loss (alopecia) in chemotherapy (not 100% guaranteed).
• Cooling reduces local blood flow/hair follicle metabolic uptake of chemotherapeutic agents.

Blood Count Monitoring (FBC)

• Checks leukocytes (for immunosuppression), platelets (bleeding risk), and RBCs (anemia) during chemotherapy.
• Repeated blood samples track chemotherapy toxicity, guiding dosage adjustments.

Test your knowledge of cancer prevention strategies, risk factors, and viral associations. Topics include oropharyngeal, cervical, and liver cancers. Identify key preventative measures and understand the etiology of different cancers.