It is well-accepted that the prognosis for cancer survival is highest when detected at early stages. This can be seen when you examine the 5 year survival rate based on stage of detection stage.
For example, for colorectal cancer, stage one detection has more than a 90% survival rate, while stage three and four detection survival rate is as low as 10%. For breast cancer, stage one has almost a 100% survival rate, while stage four cancer has only 22%.
Yet, the majority of patients in majority of cancer cases are detected in late stage. For example fewer than 30 percent of people with cancer in India survive for more than five years after their diagnosis, a sign that cancer is diagnosed only at a later stage.