For colon and rectal cancer in older patients, the survival differences seems to be in the first year – once the older patients survive the first year, their survival aligns more with the younger patients. Research questions in the national cancer registry data:
1) Do we see the same in the Swiss population, also stratified for stage and sex?
2) Is the pattern the same if we look at colon and rectal cancer specific survival?
3) Some studies show a decrease in this first-year excess mortality over time – do we see that in the Swiss population?

Older melanoma patients are diagnosed with a higher Breslow thickness and seem to have a worse survival, although the survival gap between young and older seems to close in the last years. However, survival of patients over the age of 80 years seems to lack behind, but not much is known about this group and whether this is especially true for older males (contrary to females) and stage IV (contrary to localized disease). Research questions, using national cancer registry data:
1) Is there a survival gap in relative or cancer-specific survival between younger, older and the oldest patients is the Swiss population?
2) Are there differences between males and females and localized versus metastatic?
3) Had the survival gap decreased over time, stratified by sex and stage?

For the oldest patients with prostate cancer, excess mortality (Observed mortality – Expected mortality / number of patients) seems to increase again at older age, possibly caused by a reduction in competing mortality or as a result of less aggressive treatment. Research questions, using data from the national cancer registry:
1) Using relative survival analyses, what is the observed mortality versus the expected mortality – and consequently the excess mortality for age groups in the Swiss population?
2) Does this align with cancer-specific mortality, so prostate cancer versus other causes mortality for the different age groups?

Many studies have shown that breast cancer survival in older patients is worse than in younger patients, some have shown that differences are reducing over time, but survival differences remain for older patients with metastatic breast cancer, probably due to challenges in systemic treatment. Research questions, using data from the national cancer registry: Selecting breast cancer patients with metastatic breast cancer, do we see differences in the age groups (70-75, 76-80 and 80+) in
a) Treatment?
b) Tumor types (ER+/-, HER2+/-, TN)?
c) Localization metastases?
d) Survival?
e) Survival over time?

With the introduction in 2015 of immunotherapy for NSCLC, survival has improved markedly; however, studies show that older patients may not benefit from these improvements, especially those above the age of 80 years. Research questions, using national cancer registry data:
1) Has treatment for NSCLC changed in the last years for the Swiss population, according to age, sex and stage?
2) Has relative or cancer specific survival changed over the last 10/15 years for NSCLC patients, according to age, sex and stage?

With the relatively good and improving prognosis for patients with stage I-III breast cancer, late recurrences, new primary tumors and late side-effects of treatment may occur. Besides, not much is known about the conditional survival of older patients. Research questions: How is the conditional relative and cancer-specific survival for Swiss breast cancer survivors (conditioning on surviving one or 5 years up to 15 years) for specific age groups, stratified by stage?