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Season
and Survival: cancer survival depends on season of diagnosis and vitamin
D intake
Jacob
Schor, ND
May
8, 2006
Subject:
Vitamin D levels determine long term survival of cancer patients.
As
cancer treatment becomes progressively more high tech and more expensive,
it behooves us to not overlook the simple, inexpensive adjuncts to treatment
that can improve outcomes. Research in recent years suggests that something
as simple as getting more sun light or taking vitamin D-3 in supplement
form might make a huge difference.
In
October of 2005 Harvard researchers published work that showed survival
of lung cancer patients varied with the time of year they first underwent
surgery. Summer surgery improved 5-year survival from 40% to 50%. When
information about dietary intake of Vitamin D was calculated into these
figures the differences were more pronounced. Patients who had surgery
during the summer with the highest vitamin D intake had a 5 year survival
rate of 56% compared to 23% for those who had surgery in the winter and
a low Vitamin D intake. [i]
A new study published on May 2, 2006 expands these observations by looking
at other cancers. Researchers from King's College, London , writing in
the International Journal of Cancer reported their analysis on data on
cancers of the breast, colorectum, lung, and prostate
They
used population-based data from the Thames Cancer Registry to analyze
cancer survival 1 and 5 years after diagnosis. The analysis included season
of diagnosis and sunlight exposure in the preceding months. They found
substantial seasonality in cancer survival, with diagnosis in summer and
autumn associated with improved survival compared with that in winter,
especially in female breast cancer patients and both male and female lung
cancer patients. [ii]
When
these data are added to the already existing published work on vitamin
D and both its protective and therapeutic effects in regard to cancer,
the role of something as simple as sunlight in cancer treatment becomes
even more important. How much would it cost to have cancer patients go
outside in the sunlight daily? How much would it cost to supply them with
a vitamin D supplement? At this point to not do so seems almost criminally
negligent on the part of caregivers.
For
prior newsletters on vitamin D go to http://www.denvernaturopathic.com/news.html#vitaminD
References:
[i]
Vitamin D is associated
with improved survival in early-stage non-small cell lung cancer patients.
Zhou
W , Suk
R , Liu
G , Park
S , Neuberg
DS , Wain
JC , Lynch
TJ , Giovannucci
E , Christiani
DC .
Occupational Health Program, Department of Environmental Health, Harvard
School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.
Vitamin D may inhibit the development and progression of a wide spectrum
of cancers. We investigated the associations of surgery season and vitamin
D intake with recurrence-free survival (RFS) and overall survival in 456
early-stage non-small cell lung cancer patients. The data were analyzed
using log-rank test and Cox proportional hazards models. The median (range)
follow-up time was 71 (0.1-140) months, with 161 recurrence and 231 deaths.
Patients who had surgery in summer had a better RFS than those who had
surgery in winter (adjusted hazard ratio, 0.75; 95% confidence interval,
0.56-1.01), with 5-year RFS rates of 53% (45-61%) and 40% (32-49%), respectively
(P = 0.10, log-rank test). Similar association between surgery season
and RFS was found among the 321 patients with dietary information (P =
0.33, log-rank test). There was no statistically significant association
between vitamin D intake and RFS. Because both season and vitamin D intake
are important predictors for vitamin D levels, we investigated the joint
effects of surgery season and vitamin D intake. Patients who had surgery
during summer with the highest vitamin D intake had better RFS (adjusted
hazard ratio, 0.33; 95% confidence interval, 0.15-0.74) than patients
who had surgery during winter with the lowest vitamin D intake, with the
5-year RFS rates of 56% (34-78%) and 23% (4-42%), respectively. Similar
associations of surgery season and vitamin D intake with overall survival
were also observed. In conclusion, the joint effects of surgery season
and recent vitamin D intake seem to be associated with the survival of
early-stage non-small cell lung cancer patients.
[ii]
Cancer survival is
dependent on season of diagnosis and sunlight exposure.
Lim
HS , Roychoudhuri
R , Peto
J , Schwartz
G , Baade
P , Moller
H .
King's College London ,
Thames
Cancer Registry, London ,
United Kingdom .
Sunlight is essential for the production of vitamin D in the body. Evidence
exists to suggest that vitamin D metabolites may have a role in tumor
growth suppression. In this large study, involving over a million cancer
patients from the United Kingdom ,
we have analyzed the role of season of diagnosis and sunlight exposure
in cancer survival for cancers of the breast, colorectum, lung, prostate
and at all sites combined. We used population-based data from the Thames
Cancer Registry to analyze cancer survival in periods 0-1 and 0-5 years
after diagnosis. The analysis was performed using Cox proportional regression
analysis adjusting for age and period at diagnosis and including season
of diagnosis and sunlight exposure in the preceding months as factors
in the analysis. We found evidence of substantial seasonality in cancer
survival, with diagnosis in summer and autumn associated with improved
survival compared with that in winter, especially in female breast cancer
patients and both male and female lung cancer patients (hazard ratios
0.86 [95% CI 0.83-0.89], 0.95 [95% CI 0.92-0.97] and 0.95 [95% CI 0.93-0.98]
respectively). Cumulative sunlight exposure in the months preceding diagnosis
was also a predictor of subsequent survival, although season of diagnosis
was a stronger predictor than cumulative sunlight exposure. We found seasonality
in cancer survival to be stronger in women than in men. Our results add
to a growing body of evidence that vitamin D metabolites play an important
role in cancer survival. (c) 2006 Wiley-Liss, Inc.
PMID: 16671100 [PubMed - as supplied by publisher]
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