The Cheerful Oncologist

The season in which cancer is diagnosed appears to affect survival, as does sunlight exposure to some extent, according to a study published in the October issue of the International Journal of Cancer.

Talk about not having any control over your health - not only do some of us get cancer, but now there is evidence that the season in which we are diagnosed may influence our chance for survival. Not to be frivolous, but is this akin to getting a crappy lower double berth on the Titanic?

Patients who were diagnosed with cancer in summer and autumn had better survival compared to those diagnosed in winter. This was especially true in female breast cancer patients and both male and female lung cancer patients

This observation raises comparisons to seasonal affective disorder, which is thought to be caused by a lack of sunlight in the winter months, and can be treated. I'm not so sure that there is a special treatment for patients who get cancer in the winter months, but as always it helps to start with a hypothesis. The study authors have their own as to why sun exposure provides a survival benefit:

"Sunlight is essential for the production of vitamin D in the body," Dr. Hyun-Sook Lim, of King's College London, UK, and colleagues write. "Evidence exists to suggest that vitamin D metabolites may have a role in tumor growth suppression."

Now wait just a minute! First they tell us to stay out of the sun in order to reduce the risk of getting melanoma and skin cancer, now it seems that sun exposure protects patients with newly diagnosed tumors, albeit solid ones. Is this a paradox or what?

Hey, why am I on the hot seat? I'm just a private in this epic battle. I guess if I had to come forth with an experiment though I would see if taking supplemental vitamin D improved the survival rate of these cancers, and where better to start than a country where the sun don't shine during the winter months?

Vitamin D3 from sunlight may improve the prognosis of breast-, colon- and prostate cancer (Norway)

In this study Norway was divided into eight different regions with similar solar ultaviolet radiation and climate, then 115,096 Norwegians with breast, colon or prostate cancer were matched with their region of residence, the season in which they were diagnosed, and their survival. The conclusion:

No geographic variation in case fatality was observed for the three cancer types studied. A significant variation in prognosis by season of diagnosis was observed. Diagnoses during summer and fall, the seasons with the highest level of vitamin D(3), revealed the lowest risk of cancer death.

Wait a minute! This study didn't take into account whether or not patients were on oral vitamin D or not. Is taking vitamin D an adequate substitute for sun exposure? The answer is far from certain, but one study suggests that both sunlight and oral vitamin D supplementation can both help patients improve their chances for survival after surgery for early lung cancer:

In summary, for early-stage NSCLC patients, patients who had surgery in summer with "high" recent vitamin D intake have a statistically significantly improved RFS [relapse-free survival] and OS [overall survival] than patients who had surgery in winter with "low" vitamin D intake. These results should be confirmed in a prospective study to assess the serum vitamin D levels at time of surgery. If the results are confirmed, our results, combined with findings in other studies, suggest that dietary vitamin D supplementation may be advisable for early stages of lung cancer patients, particularly during the winter season and in groups that tend to be deficient in vitamin D.

It's time to let the world know that sunlight (with sunscreen on, of course) and vitamin D (does this include a double scoop of chocolate mocha delight?) can improve the odds of beating cancer. A word to the wise should be sufficient - but it never is.