Early diagnosis of cancer focuses on detecting symptomatic patients as early as possible so they have a better chance for successful treatment. It was estimated that around 8,50,000 cancer related deaths were reported in India in the year 2020 with lip and oral cavity cancer, breast cancer and cervical cancer leading the number of cancer related deaths. Not only does the country have a high burden of cancer, around 75-80% of the patients have advanced disease ( stage 3 or stage 4 cancers) at the time of diagnosis. The situation is even worse in the rural parts of the country, which make 69% of the total population, as patients and families have to travel long distances to avail the services of a tertiary oncology center. When cancer care is delayed or inaccessible, it directly affects the efficacy of a line of treatment employed. Early detection of cancer improves outcomes by providing care at the earliest possible stage.
Cancer Screening
Cancer screening refers to a process whereby various tests are conducted across a healthy population to identify individuals who have cancer but haven’t shown any symptoms. Some of the most commonly used tests include mammography or clinical breast exam for breast cancer, pap smears, human papillomavirus tests and visual inspection with acetic acid for cervical cancer among many others.
Screening programmes or procedures should only be conducted when there is substantial evidence regarding their effectiveness. Lack of evidence regarding the effectiveness of a screening test brings with it various undesirable effects which include –
- False positive screening tests that prompt additional testing, invasive diagnostic processes and increased patient anxiety.
- False negative screening tests that provide false reassurance and can result in delayed diagnosis.
- Over diagnosis/treatment of preclinical cancers (explain ??) that could never have caused symptoms nor which pose a serious health threat.
Due to these negative effects of screening procedures, screening tests are recommended for a few cancer types. Due to this, mass population screening can only be advocated for only certain cancers such as cervical, breast and colorectal cancers.
Differences Between Early Diagnosis and Screening Methods
While cancer screening may be limited to only certain types of cancers and focuses on detecting cancer before any symptoms appear, early diagnosis lays emphasis on rapid patient presentation and beginning treatment as soon as first symptoms appear. Diagnosis of cancer at an early stage in combination with prompt treatment allows for less aggressive treatment methods thereby ensuring that a patient doesn’t have to deal with the severe effects of cancer treatment while simultaneously improving treatment outcomes. Early diagnosis is contingent upon a patient’s awareness of the early symptoms of a cancer and training of healthcare workers to recognize and appropriately refer patients with probable early cancer symptoms. Early diagnosis is a significant component of detecting cancers at an initial stage since not every individual is invited for a screening programme and these programmes may not be a feasible option for all types of cancers.
Population awareness programmes, trained healthcare professionals, prompt referral systems and diagnostic and therapeutic infrastructure are all necessary if screening methods and early diagnosis is to function optimally.
Tests To Diagnose Cancer
If a patient is exhibiting certain symptoms or a screening test that suggests the presence of cancer, the oncologist will ask for some tests to clearly examine whether it is due to cancer or some other cause. There is no single test that can confirm the presence of cancer and an oncologist usually asks for a series of tests to be conducted to effectively understand the same. The oncologist may start by examining a patient’s and their family’s medical history and a physical exam. They may order lab tests, imaging tests (scans) or other tests and procedures and even a biopsy to diagnose and identify the stage of a cancer. Some lab tests conducted to effectively diagnose cancer include:
1.Blood Chemistry Test
A blood chemistry test measures the amounts of substances such as metabolites, electrolytes, fats, sugars and proteins that are released into the blood by the organs and tissues of the body. Blood chemistry tests give important information about the functionality of liver and kidney. High or low levels of these substances can indicate the presence of a disease in the body with cancer being one of the possibilities.
2. Complete Blood Count (CBC)
The CBC test is responsible for the measurement of the number of red blood cells, white blood cells and platelets in your blood. Along with this it also measures the amount of hemoglobin (the protein that carries oxygen in the blood), the amount of your blood that is made up of red blood cells (hematocrit), the size of the red blood cells and the amount of hemoglobin in the red blood cells. CBCs can help to detect blood cancers such as leukemia and are used to monitor a patient’s health during and after treatment.
3. Immunophenotyping
This test uses antibodies to identify cells based on the types of antigens or markers on the surface of the cells. This test is usually conducted on the blood or bone marrow samples. Immunophenotyping helps to diagnose and determine the stage of blood cancers and other disorders such as leukemias, lymphomas, myelodysplastic syndromes and myeloproliferative disorders.
4. CT Scan
A CT scan (Computed Tomography scan) uses X-ray linked to a computer to take a series of images of a patient’s organs from different angles. These images are then utilized to develop detailed 3D images of a specific organ of the body. CT scans can show a tumor’s size, shape and location. They can even show the blood vessels that feed the tumor. By comparing CT scans, an oncologist can see how a tumor is responding to treatment.
5. MRI
A magnetic resonance imaging test uses a powerful magnet and radio waves to take pictures of your organs in the form of slices. An MRI scan takes cross sectional slices (views) from various angles. These slices are then combined to develop detailed images of the body, to determine the presence of tumor.
6. Nuclear Scan
A nuclear scan uses radioactive material to take a series of pictures of the inside of the body. This type of test is also referred to as radionuclide scan. Before this scan a patient receives an injection of a small amount of radioactive material, sometimes also referred as the tracer. During the test, the patient lies still on the table while a machine called a scanner detects and measures the radioactivity in the body, creating pictures of bones or organs on the computer screen.
7. Bone Scan
A type of nuclear scan, bone scans help an oncologist to determine the damage in the patient’s bones. This type of test can help to diagnose any kind of bone cancer or whether the cancer has metastasized to the bones. Before this test is conducted a small amount of radioactive material is injected into a patient’s vein. As the radioactive material travels through the blood, the material collects in the abnormal areas of the bone. These areas are referred to as ‘hot spots’ and are displayed on the images taken by the scanner.
8. PET Scan
A PET scan is a type of nuclear test that makes 3D images of the organs where the glucose is taken up in the body. Since cancer cells take up more glucose than the healthy cells of the body, the test can be used to detect cancer cells in the body. Before the test, the patient receives an injection of a tracer called radioactive glucose. During the test, a patient lies still on a table that moves back and forth through a scanner.
9. Ultrasound
Also called sonography or ultrasonography, an ultrasound is used to find a tumor by displaying the exact location of a tumor in the body. It uses high frequency sound waves to create images of the internal organs of the body. The sound waves are sent and bounce back when they reach the organs and a device called a transducer is used to turn sound waves into images. The sound waves echo or bounce differently when they hit an abnormal tissue. This helps oncologists to detect the presence of a tumor.
10. Biopsy
In most cases, oncologists need to conduct a biopsy to be certain that a patient has cancer. A biopsy is a procedure in which a doctor removes a sample of abnormal tissue. A pathologist closely examines the tissue under a microscope and describes the details in the pathology report of the patient. The information in the pathology report is important for an oncologist to determine a line of treatment that would be suitable for a patient.
Cancer Awareness
Cancer awareness is the key to early detection and improved chances for a successful treatment method. Poor awareness may lead to poor uptake of screening modalities and delay in diagnosis. Awareness pertaining to cancer in India appears to be a stiff challenge especially considering its 1.3 billion population is spread across 29 states and 7 union territories, with varying degree of population genetics and lifestyle differences resulting in a heterogeneous disease burden. In low and middle income countries, patients with cancer have a poorer prognosis than patients in high income countries. The reason behind this disparity primarily stems from lack of awareness, late diagnosis and poor access to curative services. With the increasing trend of cancer in India, the awareness level is expected to change and so is the attitude towards cancer screening. Studies on cancer awareness and attitude towards screening in India are limited, awareness about cancers and cancer screening procedures will help in early diagnosis and subsequent treatment and better outcomes.
Early Symptoms For Common Cancer
1. Lung Cancer
India is the second largest consumer and third largest producer of tobacco in the world. Approximately 28.6% of the Indian population indulges in tobacco products. In India lung cancer accounts for 5.9% of all cancers and 9.1% of all cancer related deaths. Some early symptoms that may indicate the presence of lung cancer include –
- Coughing that gets worse or doesn’t go away
- Chest Pain
- Shortness of breath
- Wheezing
- Coughing up blood
- Fatigue
- Weight loss without any discernible reason
2. Oral Cancer
Oral cancer is the most common cancer in India amongst men (11.28% of all cancers) and the fifth most occurring cancer among women (4.3% of all cancers). When oral cancer is diagnosed early, the 5 year survival rate is above 80%, whereas it is less than 20-30% for the advanced stage of the disease. Some early symptoms that may indicate the presence of oral cancer include –
- A red or white patch in or around the mouth
- A sore that bleeds easily and doesn’t heal
- A thick or hard spot, a lump
- A roughened or crusted area
- Numbness
- Pain or tenderness
- Problems chewing, swallowing, speaking or moving your tongue or jaw
- A feeling something is caught in the throat
- Pain in the throat that doesn’t go away
3. Breast Cancer
The most common cancer type among women, breast cancer accounts for 14% of cancers in Indian women. More than 50% of Indian women are diagnosed with stage 3 or stage 4 breast cancer with post cancer survival reported at 60% for Indian women as compared to 80% for women in the USA. Some early symptoms that may indicate the presence of breast cancer include –
- A lump in the breast or armpit
- Skin redness
- Dimpling or puckering in the breast
- Scaliness on the nipple
- Discharge on the nipple
- Ulcer on the breast or nipple
- Thickening of the skin, resulting in an orange peel texture
4. Cervical Cancer
Cervical cancer is the second most leading cause for cancer related mortalities among women in India. 25% of all global deaths due to cervical cancer occur in India. Lack of effective screening methods and late diagnosis contribute significantly to this outcome. The overall 5 year survival of 46% for all cervical cancers in India is strongly determined by the stage at diagnosis, with survival as low as 7.4% for advanced stage disease compared to 73.2% for localized cancer. Some early symptoms that may indicate the presence of cervical cancer include –
- Vaginal bleeding between periods
- Menstrual bleeding that is heavier than usual
- Pain during intercourse
- Bleeding after intercourse
- Pelvic pain
- A change in vaginal discharge such as more discharge or a strong colour or smell
- Vaginal bleeding after menopause
5. Esophageal Cancer
With an incidence rate of 5.04%, esophageal cancer is the most common cancer in men and the 6th most common cancer among women in India. Some symptoms that may indicate the presence of this cancer include –
- Difficulty and pain with swallowing, particularly when eating meat, bread or raw vegetables.
- Pressure or burning in the chest
- Indigestion or heartburn
- Vomiting
- Unexplained weight loss
- Coughing or hoarseness
- Pain behind the breastbone or in the throat
Summary
The importance of early detection in the fight against cancer cannot be overstated. Through consistent screenings, routine examinations, and increased public knowledge, we can identify cancer in its first stages and thereby provide hope and a more promising future for patients impacted by this illness.
