Average five-year net survival from cancer has increased markedly

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Average five-year net survival from cancer has increased markedly over time, reflecting improvements in survival for specific cancers but also, to some extent, increased predominance of cancers with more favourable prognoses, according to the National Cancer Registry annual report for 2021, which presents complete cancer information up to the end of 2019. 

Dr Deirdre Murray
Dr Deirdre Murray

Almost 200,000 cancer patients or former cancer patients were alive in Ireland at the end of 2019 (about 4% or 1 in 25 of the Irish population). The top six most common cancers among survivors were, breast cancer (23% of all cancer survivors), prostate cancer (21%), colorectal cancer (12%) and skin melanoma (7%), non-Hodgkin lymphoma (4%) and lung cancer (4%) which together accounted for 71% of all cancer survivors. These figures excluded non-melanoma skin cancers.

The report said it was still too early to see if the pandemic had led to any reduction in the number of cancers diagnosed in 2020 or on survival outcomes of cancer patients.

 “About 1 in 2 people will be diagnosed with some form of invasive cancer (excluding non-melanoma skin cancer) in their lifetime,” said the annual report.  Most cancers show static or declining trends in both incidence and mortality rates.  Recent or ongoing increases in mortality rates are seen for only a small number of cancer types (liver cancer in both sexes, mouth and pharynx cancer in males, and uterine cancer and melanoma of skin in females), broadly in line with upward incidence trends for these cancers.  Other cancers with increasing incidence rates show stable or declining mortality rates (i.e. Hodgkin lymphoma in both sexes, thyroid cancer in males, breast and kidney cancer in females).

Dr Jerome Coffey
Dr Jerome Coffey

For invasive cancers as a whole (excluding non-melanoma skin cancers), five-year net survival averaged 65% for patients diagnosed during 2014-2018, compared with only 42% for those diagnosed during 1994-1998: a very substantial increase.  Major improvements in survival have also been seen for most major cancer types, though survival still varies markedly by cancer type. Although the cancers with the poorest average prognosis may not have shown ‘absolute’ increases in survival as high as seen for some cancers, relative increases in survival have still been substantial, including more than a doubling of survival for oesophageal, pancreatic, liver and lung cancer since the 1990s. 

Five-year net survival of patients diagnosed during 2014-2018 varied widely by cancer type, from only 14% for pancreatic cancer, 18% for liver, 24% for oesophageal and lung, and 25% for brain cancer, to 88% for thyroid and female breast cancer and for Hodgkin lymphoma, 93% for melanoma of skin, 94% for prostate and 96% for testicular cancer.  Improvements in average five-year net survival, expressed as absolute gains comparing diagnosis period 1994-1998 with 2014-2018, were highest for multiple myeloma (+37 % points), prostate cancer (+30%), non-Hodgkin lymphoma (+27%), leukaemia (+23%) and small intestinal cancer (+22%); and lowest for laryngeal (+4%), brain (+6%), uterine (+6%) and testicular cancers (+7%), bladder tumours (+8%) and ovarian and related cancers (+9%). Absolute changes in survival since 1994-1998 do not convey the full picture, however, as modest percentage-point improvements for high-fatality cancers may also represent substantial improvements in relative terms: most notably, more than a doubling of survival seen for cancers of the oesophagus (from 11% to 24%), pancreas (from 5% to 14%), liver (from 5% to 18%) and lung (from 8% to 24%).

Of all deaths occurring in 2018 in Ireland, 31% (almost 1 in 3) were attributable to cancer. Another 29% and 13% were attributable to diseases of the circulatory and respiratory systems respectively. On average there were 9,190 deaths per year from invasive cancer (4,864 in males, 4,326 in females) during the period 2016-2018, or 9,423 deaths per year from any tumour type.

Lung cancer was the leading cause of cancer death in both sexes during 2016-2018.  In males, cancer of the bowel, prostate and oesophagus were the 2nd, 3rd, and 4th most common categories of cancer deaths, respectively.  In females, cancer of the breast, bowel and ovary were the 2nd, 3rd and 4th most common categories of cancer deaths, respectively.

Colorectal cancer cases in males increased significantly and steadily during the period 1994-2015 followed by a plateau during 2015-2019. It is not yet clear to what extent the national bowel screening programme (BowelScreen), introduced in late 2012, may have influenced these trends.

There were increases in the incidence rate for melanoma in males and females, lung cancer in females, prostate cancer, kidney cancer in males (during 1994-2012), kidney cancer in females (during 1994 – 2012), non-Hodgkin lymphoma in males and females, multiple myeloma,  mouth and pharyngeal cancer in females, liver cancer in females, uterine cancers, cervical cancer  (1999 – 2009), followed by a significant decline during 2009-2019, breast cancer 1994-2002, followed by a significant decline during 2009-2019.