Frequently Asked Questions About Cancer

Cancer is a disease in which abnormal cells grow uncontrollably, invade surrounding tissues, and sometimes spread to other parts of the body.

Cancer develops due to changes in the genetic material of cells. These changes may occur because of:

• Tobacco consumption and smoking.
• Alcohol consumption.
• Certain infections, such as human papillomavirus (HPV) and hepatitis B or C.
• Exposure to ultraviolet radiation and certain environmental carcinogens.
• Inherited genetic mutations.
• Age-related accumulation of cellular damage.
• Obesity, physical inactivity, and certain dietary factors.

In many cases, cancer develops through a combination of factors, and the exact cause may not be identifiable.

Most cancers are not inherited directly. However, approximately 5–10% of cancers are associated with inherited genetic changes that increase cancer risk. Examples include inherited BRCA1 and BRCA2 mutations associated with breast and ovarian cancer.

No. Cancer itself does not spread from one person to another through touching, hugging, sharing food, or living together. However, certain infections associated with cancer risk can be transmitted between people.

Yes. Cancer can occur at any age, including childhood and adolescence, although the types of cancer and their frequency vary by age.

Possible warning signs include:

• An unexplained lump or swelling.
• Unintentional weight loss.
• Persistent fatigue.
• Unusual bleeding or discharge.
• A persistent cough or hoarseness.
• Changes in bowel or bladder habits.
• Difficulty swallowing.
• A sore that does not heal.
• Changes in the size, shape, or colour of a mole.
• Persistent, unexplained pain.

These symptoms do not necessarily indicate cancer, but persistent or unexplained changes should be evaluated by a healthcare professional.

No. Many cancers do not cause pain in their early stages. Therefore, the absence of pain does not rule out cancer.

Yes. Some cancers, including early breast, cervical, and colorectal cancers, may cause few or no symptoms. This is one reason why appropriate screening is important.

No. Many lumps are benign, such as cysts or lipomas. However, a new, enlarging, hard, or persistent lump should be assessed by a healthcare professional.

Not all cancers can be prevented, but certain lifestyle changes and preventive interventions can significantly reduce the risk. These include:

• Avoiding tobacco in all forms.
• Avoiding or limiting alcohol.
• Maintaining a healthy body weight.
• Exercising regularly.
• Eating a balanced diet rich in vegetables, fruits, and whole grains.
• Protecting the skin from excessive ultraviolet exposure.
• Receiving HPV and hepatitis B vaccinations when appropriate.
• Participating in recommended cancer screening programmes.

Cancer screening involves testing people who do not have symptoms to identify certain cancers or precancerous changes at an early stage. Examples include:

• Breast cancer: Mammography for eligible individuals.
• Cervical cancer: HPV testing and/or cervical cytology (Pap testing), according to applicable guidelines.
• Colorectal cancer: Stool-based tests or colonoscopy, depending on age and risk.
• Oral cancer: Clinical oral examination, particularly important for people with tobacco or areca nut exposure.

Screening recommendations depend on age, sex, family history, individual risk, and local guidelines.

No. Whole-body CT scans, PET scans, and tumour-marker panels are not recommended as routine screening tests for every healthy individual. They may produce false-positive results, unnecessary investigations, radiation exposure, or other harms.

Screening should be tailored to established recommendations and individual risk.

No. Currently, there is no single routine blood test that reliably detects all cancers. Blood tests may help evaluate symptoms, assess organ function, or monitor selected cancers, but they do not replace appropriate screening and diagnostic investigations.

Cancer diagnosis may involve:

• Medical history and physical examination.
• Blood and other laboratory tests.
• Imaging, such as ultrasound, CT, MRI, or PET-CT, when indicated.
• Biopsy and histopathological examination.
• Molecular or genetic testing in selected cases.

A biopsy is required to confirm most cancers, although the precise diagnostic approach depends on the suspected cancer type.

A biopsy involves removing a sample of tissue or cells for examination under a microscope. It helps determine whether cancer is present and, in many cases, identifies its type and characteristics.

Cancer stages generally describe the extent of the disease.

• Stage 0: Abnormal or in-situ cells that have not invaded surrounding tissue.
• Stage I: Cancer is generally localized and relatively limited.
• Stage II: Cancer may be larger or involve nearby tissues or lymph nodes, depending on the cancer type.
• Stage III: More extensive local or regional disease.
• Stage IV: Cancer has spread to distant parts of the body; this is called metastatic cancer.

The exact staging criteria differ considerably among cancer types. Not every cancer uses the same staging system.

Some benign tumours can still cause serious problems because of their size or location.

The major treatment modalities include:

• Surgery: Removes a tumour when appropriate.
• Radiation therapy: Uses radiation to destroy cancer cells.
• Chemotherapy: Uses medicines to kill or inhibit rapidly dividing cancer cells.
• Immunotherapy: Helps the immune system recognize or attack cancer cells.
• Targeted therapy: Acts on specific molecular abnormalities involved in cancer growth.
• Hormone therapy: Blocks or reduces hormones that promote the growth of certain cancers.
• Stem cell transplantation: Used in selected blood cancers and other specific conditions.

Many patients receive a combination of treatments.

No. Some cancers can be treated effectively with surgery, radiation therapy, targeted therapy, immunotherapy, hormone therapy, or combinations of these approaches. Treatment depends on the cancer type, stage, molecular characteristics, and the patient’s overall health.

Chemotherapy generally affects rapidly dividing cells through mechanisms that are not specific to one tumour alteration.

Targeted therapy acts on particular molecular targets or pathways involved in cancer growth and survival. It is often prescribed after appropriate biomarker testing.

Targeted therapies can also cause significant side effects, and not every patient is eligible for them.

Immunotherapy is a treatment that helps the immune system recognize or attack cancer cells. Examples include immune checkpoint inhibitors, certain cellular therapies, and monoclonal antibodies with immune-related mechanisms.

Immunotherapy is effective in selected cancers, but it does not work for every patient and can cause immune-related side effects.

Yes. Many cancers can be cured, particularly when diagnosed and treated at an early stage. Some advanced cancers can also be cured, depending on the type.

When cure is not possible, treatment may control the disease, relieve symptoms, prolong life, and improve quality of life.

• Complete remission: No detectable evidence of cancer using the available assessment methods.
• Partial remission: The cancer has decreased significantly but has not disappeared completely.
• Cure: The cancer has been eliminated with no expectation that it will return, although absolute certainty is not always possible.
• Recurrence: Cancer returns after a period when it was undetectable or controlled.

Remission does not always mean that a cancer has been permanently cured.

Depending on the treatment, side effects may include:

• Fatigue.
• Nausea and vomiting.
• Hair loss.
• Reduced appetite.
• Mouth ulcers.
• Diarrhoea or constipation.
• Low blood cell counts.
• Increased susceptibility to infections.
• Skin changes.
• Nerve damage or numbness.
• Hormonal changes.

Not every patient experiences these effects, and many can be prevented or managed with supportive care.

Many can, although dietary needs may change during treatment. A balanced diet with adequate calories, protein, fluids, and micronutrients is generally important.

Diet should be individualized according to symptoms, nutritional status, treatment, and other medical conditions. Patients should consult their oncology team before taking supplements or following restrictive diets.

No. There is no good clinical evidence that eliminating all dietary sugar treats cancer or causes tumours to disappear.

Cancer cells use glucose for energy, but normal cells also require glucose. A balanced diet with limited added sugar is generally preferable to extreme dietary restriction.

Many patients can benefit from appropriately tailored physical activity. Exercise may help reduce fatigue, maintain strength, and improve physical function and quality of life.

The type and intensity of exercise should be adjusted according to the patient’s condition, blood counts, symptoms, and treatment-related risks.

No. Hair loss depends on the specific drugs, their doses, and the treatment schedule. Some chemotherapy regimens cause substantial hair loss, while others cause little or none. Hair often grows back after treatment, although recovery varies.

Myth. Many cancers are curable, and advances in diagnosis and treatment have improved outcomes for numerous cancer types.

Myth. Cancer does not ordinarily spread because a tumour has been biopsied or surgically removed. These procedures are standard parts of cancer diagnosis and treatment. Tumour seeding is a rare complication in specific circumstances.

There is no reliable scientific evidence that herbal remedies alone can cure cancer. Some complementary approaches may help with selected symptoms, but they should not replace proven cancer treatment. Certain herbs and supplements can also interact with anticancer medicines.

No. Tumour markers may be elevated in some benign conditions and may remain normal in people who have cancer. They are interpreted in conjunction with symptoms, imaging, pathology, and other clinical findings.

Yes. Recurrence is possible, depending on the cancer type, stage, and treatment response. Regular follow-up helps monitor recovery, identify potential recurrence, and manage long-term effects.

Yes. Fear, sadness, anger, uncertainty, and anxiety are common responses. Psychological support, counselling, support groups, and appropriate mental health care can help patients and families cope.

• Listen without judging.
• Respect the patient’s choices and privacy.
• Accompany them to appointments if they wish.
• Help with meals, transport, and daily activities.
• Encourage appropriate treatment and follow-up.
• Avoid giving unproven treatment advice.
• Recognize caregiver fatigue and seek support when needed.

Palliative care focuses on improving quality of life by addressing pain, other physical symptoms, psychological distress, and social or spiritual concerns.

It can be provided alongside cancer-directed treatment at any stage of illness. It does not necessarily mean that treatment has stopped or that death is imminent.