In the first article I discussed warning symptoms of common cancers in male and females; early detection entails bringing them to the notice of a physician and getting them appropriately investigated. We commonly ignore early symptoms and self medicate ourselves, only to face problems later on.
The second important way of early detection is screening, of healthy individuals. There are 5 screening modalities which have shown to decrease cancer mortalities by means of early detection and are approved for use.
BREAST AWARENESS, CLINICAL BREAST EXAMINATION AND MAMMOGRAPHY
Creating breast awareness among females is important so as they learn self breast examination, and this should start from the age of 25 yrs. Clinical breast examination – by an expert doctor, can be offered once in 1-3 yrs after the age of 25 yrs and more frequently after 40 yrs of age, especially for those who are at high risk or have family history.
Mammography is an X ray examination of the breast which can detect early tumors and is recommended once in a year after the age of 40 yrs. Routine use of annual mammography has shown to sharply decrease breast cancer mortality by early detection, in the western countries. Mammography scores the abnormality in the breast on BIRADS (breast imaging, reporting and data system) scale from 0 to 5. Score 0-3 is considered benign and warrants follow up only, where as score 4 and 5 are considered highly probable for malignancy and always warrant biopsy.
Sometimes in younger females due to denser breast, mammography needs to be complemented with ultrasonography for correct interpretation.
PAP AND HPV TEST
Cervical cancer is a health problem of the developing world and pap (papanicolaou) test is the most inexpensive way to detect it early. Pap test is the preparation of a smear of cervical cells which is then examined under a microscope to look for abnormality, based on which further examination if required is recommended. HPV (human papilloma virus) is the causative virus for all cervical cancers and spreads through sexual contact. HPV test entails detection of HPV infection in the cervical smear which increases the sensitivity of detection.
The recommendation is to start screening from age of 21 yrs (after sexual contact) once in 3 yrs with Pap test. HPV test is recommended after age of 31 yrs and should always be coupled with Pap test. If HPV is co-performed with Pap test frequency is every 5 yrs. Screening can be stopped after age 65 yrs provided last 3 Pap test are negative.
Those who have received HPV vaccine should get routine screening.
Prostate Specific Antigen (PSA) is a blood test to detect prostate cancer early. PSA screening has lately been clouded with immense controversies. Prostate cancer is commonly a disease of aged men; and PSA screening can detect such early stage cancers which actually may not become symptomatic in a patients life time. Benefits (such as early detection and cure) and risks (over-treatment) of screening need to be discussed before offering routine screening to men for prostate cancer.
LOW DOSE CHEST CT SCAN
Lung cancer is strongly associated with smoking. Latest study has shown benefit of early detection through low dose CT scan of the chest in those who are heavy smokers. Annual CT for 3 consecutive years in those with more than 30 pack years of smoking is recommended for early detection of lung cancer.
Cancers of the large intestine are amenable to early detection through internal examination via colonoscopy. This is applicable to those who have strong family history of colon cancer or have suffered from it in their own life time. Colonoscopy once in 5 yrs or earlier (depending on the risk) is the recommendation in those who are at risk.
Early detection means have made a sea change in cancer doctors mortalities in the developed world. However, their utilization requires public awareness, heath care accessibility and strong community screening programs. Needless to say, they also require adaptation to local community, and to their common cancers, keeping in mind their religious and social backgrounds. In the end, self awareness is the key.