By Giske Ursin, director of the Cancer Registry of Norway
A challenge in interpreting trends from one year to the next is that when we publish the numbers already in October the following year, the final count is not complete. This is because one of our supplemental sources, the death certificates, are still not completely electronic, and thus the information is delayed. For a small proportion of cancer cases no pathology specimen can be obtained, and consequently we receive no pathology report. We do, however, routinely receive administrative data from the Norwegian Patient Registry or a clinical report from the physician who diagnosed and treated the patient. But in some cases we do not receive the latter, and for those cases we use the death certificate information to trace back and request the missing clinical reports. This death certificate delay usually results in a slight increase in our cancer counts after publication of Cancer in Norway, in particular when we publish the numbers as early as October. We therefore include the current updated counts for the previous years in our annual report. In describing trends, we compare rates over a longer (five-year) period.
Postitve trends for lung cancer in women
Good news in this report are the longer time trends we see for lung cancer. For men, rates have been declining for some of years. The challenge has been the oldest age group, but we now see that men over 80 have had stable rates for about 7 years. Among women, the good news is that rates for women under 60 seem to be continuously declining. Even among 60–69 year olds, the rates seem to be flattening out. The only group that is still increasing is women above age 70. There are still a vast number of middle aged/older women in Norway with a heavy smoking history, and we therefore know that the number of lung cancer cases will remain substantial in the older groups for years to come. The stabilizing rates among the 60-year olds and continuous decline in younger women are, however, promising. Combined with very low smoking rates among young people, a further decrease of lung cancer rates is expected in the years to come.
A remaining concern is lung cancer rates among immigrants who come from countries with a high smoking prevalence and bring this habit with them. We are pleased to announce that our regulations were changed this year, so the Cancer Registry can now obtain information on country of birth. We plan to start reporting rates by country or region of birth next year.
Increased breast cancer rates in elderly women
Another concern is the increase in breast cancer rates in women above 70. We suspect this is caused by women having mammography examination at private clinics after the end of the organized screening program (which targets the age group 50–69). However, the Cancer Registry does not receive mammography reports from private clinics, and we therefore cannot be certain that this is the explanation.
Other good news in this report is the increasing survival, especially in advanced cancer stages for several cancers. Although survival remains low for many cancer types with distant metastases, we have seen substantial changes over time. Even for lung cancer, where survival remains very low for advanced cases, there are improvements.
- Let us build an infrastructure for medical treatment!
To better understand why survival is improving, we would need information on all aspects of cancer treatment. Our eight national clinical registries collect such information. Sadly, we miss an important part: medical treatment provided in the hospitals. This is only sporadically reported to the Cancer Registry of Norway, and is not reported to the National Prescription Database either. Our regulations do allow us to have this information. Why do we not get it? Because there is no national infrastructure to extract this information from the hospital systems. Let us build it!
When survival improves, the number of individuals living with cancer increases. In 2017, roughly 273 thousand men and women, more than 5% of our population, had a cancer diagnosis. Many of these individuals suffer from side effects of therapy or
develop late effects many years after completing the treatment. Such effects can substantially reduce quality of life. Our regulations do not enable us to systematically obtain information directly from patients, and we therefore can only assess the prevalence of such complaints in separate research studies. We currently run or plan research projects on three major cancer types, prostate, breast and colorectal cancer. We hope our regulations will be altered in the future to enable us to obtain this information systematically and routinely.
-Thank you for contributing to high quality cancer statistics
Thank you to all physicians and staff in the clinics across Norway who have reported cancer diagnosis and treatment details to the registry. Thank you also to our coders and supporting staff for meticulous coding of each cancer. Finally thank you to the statisticians and editorial team for providing the tables and writing this report.