Tuesday November 22 2011
Life expectancy with colon cancer has risen from months to ten years
Survival rates have risen dramatically for many types of cancer but have hardly improved for others, BBC News reported. Citing new figures released by the cancer charity Macmillan, the BBC said that the average estimated survival time for people diagnosed with cancer has risen from one year to nearly six years in the last four decades.
Macmillan’s new report highlights the massive improvements that have been made in some areas. For example, people diagnosed with colon cancer might typically live beyond a decade, compared to just seven months if they had been diagnosed 40 years ago. However, it appears there is a major need to boost survival rates for lung cancer, pancreatic cancer and stomach cancers, which have hardly improved despite 40 years of medical advances.
What did the report look at?
The report was compiled by Macmillan Cancer Support to estimate how long people lived on average after they were diagnosed with various types of cancer. Figures were calculated for people diagnosed at various times from 1971 to 2001, and the expected average life expectancy for people diagnosed in 2007 was predicted.
Cancer survival rates are typically presented as the percentage of patients that will still be alive five or ten years after diagnosis. Instead, this report used historic data to estimate how long on average people would currently live after diagnosis and whether this had improved in the past four decades.
The estimated average survival times for people diagnosed in 1971–72 and 2007 respectively were:
- adult leukaemia – 4 months (1971–72) and 36 months (2007)
- ovarian cancer – 8 months and 37 months
- myeloma (a type of blood cancer that can also affect bone tissue) – 5 months and 30 months
- stomach cancer – 2 months and 8 months
- oesophagus (foodpipe) cancer – 2 months and 8 months
- brain cancer – 3 months and 7 months
- pancreatic cancer – 2 months and 3 months
- lung cancer – 3 months and 5 months
- kidney cancer – 9 months and 64 months
- rectum cancer – 15 months and 106 months
- colon cancer – 7 months and 120 months
- non-Hodkin’s lymphoma and “other cancers” – 12 months and 120 months
For some cancers such as breast, cervical, Hodgkin’s lymphoma, larynx and melanoma (skin cancer), the current estimates of median survival time were not fully presented. However, data from the 1970s showed that people with these cancers had a long average survival time of at least ten years.
What does ‘median survival time’ mean?
The report calculated these estimates as “median survival times” for different types of cancer. This means the length of time after diagnosis until half of the people with that type of cancer have died.
Macmillan says some patients may want to know this statistic to answer the common question of how long someone can expect to live after their diagnosis. While this may be useful, it is important to note that this figure is an average, and half the people would be expected to live longer than this estimated “life expectancy”.
Also, outcomes for certain cancers can vary greatly depending on the stage at which cancer is first detected and the types of treatment this will allow. For example, there are generally better options for treating a cancer detected early using screening or early diagnosis techniques than one detected later due to problematic symptoms.
Other important factors need to be considered when interpreting this statistic. The report used broad categorisations of cancer, but most cancers have various subtypes depending on the type of cell in a tissue that has grown to form a tumour. These subtypes may have different probabilities of spreading in the body.
What else did the report find?
Among the various statistics in the data, Macmillan highlighted some important findings:
- People now live nearly six times longer after their cancer diagnosis than forty years ago, up from a median survival time of one year to six years.
- For eleven of the twenty cancers studied, median survival time is now over five years.
- For six of the twenty cancers, median survival time has been high at more than ten years since the early 1970s. However, for nine cancers, the median survival time has remained at three years or less.
- The greatest improvement in median survival time was for colon cancer, with a 17-fold increase from 7 months to 10 years.
- However, the median survival time for other cancers such as lung cancer has not increased greatly (from 11 to 20 weeks), and for pancreatic cancer has hardly increased at all.
The outlook for which cancers has improved the most?
The largest improvements have been for colon cancer (17-fold increase in median survival). Non-Hodgkin’s lymphoma showed a 10-fold increase, and rectal cancer showed a seven-fold increase. Breast cancer’s median survival time doubled over the 1970s, and is now longer than ten years.
The outlook for which cancers has remained the same?
The researchers found that for nine of the twenty cancers studied, the median survival time was three years or less. They found that for five of these (stomach, oesophagus, pancreatic, brain and lung cancers) there has been little improvement in median survival time over the last forty years.
What does the report recommend?
The report highlighted that although it is good news that more cancer patients are living longer overall, they may not be spending this time living well. It points out that “cancer treatment is the toughest fight many people will face and patients are often left with long-term health and emotional problems long after their treatment has ended”.
Macmillan illustrates this point by highlighting that although colorectal cancer is one of the cancers with large improvements in median survival time, 64% of people still alive five to seven years after their diagnosis have an ongoing health problem.
Macmillan said it was important that the NHS recognises the long-term impact of cancer on people’s lives to plan better services and develop more personalised care.