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.


  1. #1 promenea
    October 26, 2006

    How did they link this to vitamin D directly – just because they couldn’t think of anything else that sunlight might affect? How about the cohesion and timing of the circadian system? Longer days makes coupling in the circadian system stronger and the peak of melatonin narrower and higher. It is known that uncoupling of the circadian system and disorder in activity cycles is one predictor of death (in rodents. People also tend to die more often in the wee hours of a long night cycle.

    Also, every organ in our body is regulated in its cell division cycle by our internal circadian clock. Cancer cell division tends to be unregulated by the clock however. Perhaps it has something to do with the phase of the circadian cycle in the long night part of the cycle relative to types of toxic treatments?

  2. #2 Ted
    October 26, 2006

    Medical types like to pretend they know what they’re doing, when they’re mostly guessing. I’ve found that figuring out the optimum Neupogen or Neulasta regime to keep my white cell count high, my guesses are about as good as my medical team’s guess.

    I have read that the closer one lives to the equator, the lower of all incidences of cancer, except skin cancer. Half an hour of exposure to summer sun produces 10,000 to 12,000 units of vitamin D.

    I currently take 4,000 units a day and am considering upping it.

  3. #3 DL From Heidelberg
    October 27, 2006

    Diagnosed in the spring. Just my luck.

  4. #4 emmy
    October 27, 2006

    I was diagnosed in the spring too. Oh well, I’m alive today. I guess that will have to do.

  5. #5 Felix Kasza
    October 28, 2006

    Ted@9:33am —

    if I remember my high-school biochem correctly (do I, Dr. Hildreth?), UV turns cholecalciferol (vitamin D3) into ergocalciferol (D2). Gobbling improbable quantities of D3 seems useless unless you get enough UV to convert it — or you could get D2 supplements instead.


  6. #6 Ted
    October 29, 2006

    Maybe I’ll just go back to the tanning salon.

  7. #7 yash
    June 28, 2007

    Ice Cream Images

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