Cancer Survival – Is It Improving?

Survival statistics are of great interest to patients, clinicians, researchers, and policy markers. For cancer patients, the main statistic of interest is not population mortality, but individual survival. Survivals, not mortality, answers the question that cancer patients want to know: what is my chance of staying alive given my diagnosis? Clearly, survival is an important statistics from a clinical perspective. Different survival measures answer different questions: Overall survival (includes all causes of death), cancer prognosis (net survival that removes competing causes of death), and actual prognosis (crude probabilities that consider competing causes of death).

Cancer survival in a population is affected by a number of factors, including the types of cancer that occur, the stages at which they are diagnosed and whether treatment is available. For cancers that are more amenable to screening and /or treatment, such as female breast, colorectal, and certain childhood cancers, there are large survival differences by HDI (Human Development Index) level. For example, the 5-year survival rate for breast cancer in 2010-2014 was 90% in the US and Australia, compared with 65% in Malaysia. In contrast, for cancer sites without early detection or effective treatment, such as liver, lung, or pancreas, survival rates vary less. In addition to differences in screening and treatment, international differences in cancer survival rates are also affected by disease awareness and data quality.

Cancer survival continues to increase across high-income countries; however, international disparities persist. While truly valid comparisons require differences in registration practice, classification, stage of disease at diagnosis, timely access to effective treatment, and the extent of comorbidity are the main determinants of patient outcomes. Data has been analyzed for different cancers including Lung, colon, rectal, ovarian, oesophageal, stomach, and pancreatic cancer, and survival improvements have been noted for cancers in patients younger than 75 years. Cancer survival used to be generally higher in Australia, Canada, and Norway. Substantial progress has been made in cancer control across high income countries for stomach, colon, lung (in males), and ovarian cancer (in female). The uniform improvements in cancer survival are probably the direct consequence of major health care reforms and technological advances that have enabled earlier diagnosis, more effective and tailored treatment, and better patient management than in previous periods. For example, rectal cancer had one of the most substantial increases in 5-year net survival over time, increasing between 9 to 21 percentage in high income countries. Improvements in surgical techniques, including the implementation of total mesorectal excision and new guidelines that include preoperative radiotherapy are among the key changes that have improved patient outcomes. Improvements in survival were largely seen among younger patients (aged <75 years) and might relate to the relatively wider access to adjuvant chemotherapy and ability of these patients to tolerate more aggressive treatments than older age groups. Additionally, better diagnosis and staging with new technologies such as PET-CT imaging, alongside greater precision in the selection of patients for targeted therapies on the basis of molecular markers have improved survival. Such progress in the control of different cancer types particularly cancers of the stomach, colon, lung (in males), and ovary, can be attributed to the delivery of multiple evidence-based and effective interventions that span the spectrum of cancer control. However cancer survival in India has been dismally low.

India’s cancer graphs tell two distinct stories. The first holds out hope as India’s cancer incidence is far lower than developed nations such as Denmark and the US. If cancer strikes over 300 out of every 100,000 population in Denmark, the corresponding number in India hovers around 100. But the second Indian cancer story is worrisome. A study in medical journal, The Lancet, in 2014 indicated only 30% of India’s cancer patients survive for over five years. So while India has lower cancer rates than many other countries, it has a high death rate.Maximum cancer patients succumb to lung, head and neck and breast cancers. “We lose almost 80% of all patients detected with lung cancer. The death rate due to breast cancer world over is 20%, but we lose over 50% of our breast cancer patients”.Almost 80% of cervical cancer patients are diagnosed in stage 3-4 in India, but the West has almost eradicated this cancer due to regular pap smear tests. Given India’s population, it is impossible to scan everybody. “Self-breast exams and clinical exams involving community workers or ancillary health professionals are hence crucial,”Lack of awareness is the main cause for late detection.

A report published in the international journal, The Lancet, has also drawn attention to poor infrastructure and treatment facilities for cancer patients in India, which is leading to high cancer mortality. Nearly 70 percent cancer patients die in India; fewer than 30 percent of Indian patients with cancer survive five years or longer after diagnosis. By contrast, in North America and Western Europe, five-year survival for patients with all types of cancers is about 60 percent. Delayed diagnosis and inadequate, incorrect or sub-optimum treatment are the chief factors for poor cancer survival in India. However, investment in high-technology, and methods to take treatment to the peripheral parts of the country, is missing in the country. The effort of all research and investment in infrastructure should lead to reduced suffering due to cancer.

Initiatives have to be categorized for prevention, screening and treatment of each cancer type. At primary prevention front, awareness campaigns, stressing on life styles, food habits and physical activities are necessary. At secondary level, massive screening with newer technology and at the tertiary level, the diagnosed patients should have accessibility to best of health care facilities.

All state holders should create an ecosystem for cancer care accessibility, affordability and assurance (FICCI+EY 2017)

Dr. A. K. Dewan
Director – Surgical Oncology, RGCIRC, Delhi