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The changes in cancer incidence rates in the U.K. from 1991 to 2000
as summarized in the news account by Ferriman (1) and the National
Statistics Office indicated in (1) are very interesting. However, the
statement by Professor Robert Souhami, director of clinical and external
affairs at the charity Cancer Research UK, "The figures highlight the
worrying increase in melanoma, which has one of the fastest growing
incidences of all cancers, despite it being almost entirely preventable.
We need to persuade young people especially to change their attitudes
towards tanning and their behaviour relating to the sun and sunbeds." may
be off the mark. Skin type plays a very important role in the risk of
melanoma, with those with darker skin and the ability to tan at reduced
risk, while those with higher numbers of nevi at increased risk (2,3).
Frequent sunburning is a risk factor for melanoma (4), and should be
avoided. As for sunbed use, a recent study estimated that since 7% of the
U.K. population uses sunbeds, their use could account for 370 of the 6000
annual cases (4). Also, since melanoma generally takes 20-40 years to
develop after exposure to harmful radiation (UV or X-ray), so recent
trends can't be linked to recent changes in tanning practices. Perhaps
increased surveillance has also contributed somewhat to the increased
reported incidence of melanoma, as it has for prostate cancer (1). While
UV exposure is likely involved in a significant fraction of melanoma
incidence in the U.K. (4), there are important interactions between
frequency and duration of UV exposure with skin type, diet, body mass
index, etc.
Overlooked in the press release is the role that diet and obesity
also play in the etiology of melanoma. In a study in Washington State,
Vitamin E obtained from food was inversely related to risk of melanoma
(for highest quartile vs. lowest quartile, age-, education-, and energy
intake-adjusted odds ratio (OR) = 0.34, (95% confidence interval (CI) 0.16
-0.72; p for trend = 0.01). When intake of nutrients from food plus
vitamin and mineral supplements was considered, zinc from food and
supplements was associated with a decreased risk of melanoma (for highest
quartile vs. lowest quartile, adjusted OR = 0.46, 95% CI 0.24-0.91; p for
trend = 0.01) (5). Body mass index is an important risk factor for
melanoma, with one study finding an odds ratio of 1.90 (95% CI 1.10-3.27,
p for trend = 0.02) (5) and another (for males) 2.8 (95% CI 1.5-5.2) (6).
Daily exercise is also a risk reduction factor (6). Given the fact that
Parliament is in the middle of an ongoing series of hearings on obesity,
obesity must be on the rise in the U.K.
To check the obesity/diet hypothesis, we can consider changes in the
incidence of other cancers. Increases were noted for breast, colorectal,
prostate, and testes cancer and leukaemias and lymphomas. Breast cancer
is linked to obesity (7); colon cancer is linked to obesity (8) and
insufficient vitamin E (9); prostate cancer is linked to obesity (10);
lymphoma is linked to obesity (8). 7.8% of the burden of disease in
Europe has been attributed to obesity (11). Thus, unless another reason
can be given for the increase in these cancers, obesity must be on the
rise. To fight obesity, there has to be a concerted effort to reduce the
consumption of junk food, especially that high in sweeteners (added sugar)
(12,13).
Further support for diet and obesity is that solar UVB (280-315 nm)
radiation, through the production of vitamin D, is an important risk
reduction factor for a dozen types of cancer including breast, colorectal,
prostate, and stomach cancer (14-17), and lymphoma (16). Vitamin D may
even be a risk reduction factor for melanoma (18). Thus, if those in the
U.K. were, indeed, getting more UVB radiation in the past 10-20 years, the
vitamin D-sensitive cancer incidence rates should be decreasing with
respect to non-vitamin D-sensitive cancers such as leukaemias (the other,
non-vitamin D-sensitive cancers have specific risk factors such as tobacco
smoke or asbestos fibers). The reduction in stomach cancer may be related
to the use of antibiotics to reduce the risk from H. pylori infection.
In conclusion, those living in the U.K. would be better advised to
seek more, not less, UVB radiation and vitamin D supplementation in order
to reduce the risk of cancer. It is estimated that in the U.S.,
insufficient UVB, the major source of vitamin D in the U.S., (19) accounts
for 45,000 premature deaths and 165,000 avoidable cases annually, compared
with 10,000 deaths due to melanoma and other skin cancer [(16), Grant, in
preparation]. Since the U.K. is farther north than the U.S., and
mortality rates for vitamin D-sensitive cancers are up to twice as high in
the northeast U.S. than in the southwest U.S. (20), the cancer risk due to
insufficient vitamin D is probably much greater than in the U.S., with
perhaps 25% of breast cancer mortality in the U.K. attributable to
insufficient UVB/vitamin D (15, 16).
References
1. Ferriman A. Large increases occur in cancers of skin and prostate. BMJ
2003;327:1306.
2. White E, Kirkpatrick CS, Lee JA. Case-control study of malignant
melanoma in Washington State. I. Constitutional factors and sun exposure.
Am J Epidemiol. 1994;139:857-68.
3. Kennedy C, Bajdik CD, Willemze R, et al. The influence of painful
sunburns and lifetime sun exposure on the risk of actinic keratoses,
seborrheic warts, melanocytic nevi, atypical nevi, and skin cancer. J
Invest Dermatol. 2003;120:1087-93.
4. Diffey BL. A quantitative estimate of melanoma mortality from
ultraviolet A sunbed use in the U.K. Br J Dermatol. 2003;149:578-81.
5. Kirkpatrick CS, White E, Lee JA. Case-control study of malignant
melanoma in Washington State. II. Diet, alcohol, and obesity. Am J
Epidemiol. 1994;139:869-80.
6. Shors AR, Solomon C, McTiernan A, White E. Melanoma risk in relation to
height, weight, and exercise (United States). Cancer Causes Control.
2001;12:599-606.
7. Parker ED, Folsom AR. Intentional weight loss and incidence of obesity-
related cancers: the Iowa Women's Health Study. Int J Obes Relat Metab
Disord. 2003;27:1447-52.
8. Wolk A, Gridley G, Svensson M, et al. A prospective study of obesity
and cancer risk (Sweden). Cancer Causes Control. 2001;12:13-21.
9. Bostick RM, Potter JD, McKenzie DR, et al. Reduced risk of colon cancer
with high intake of vitamin E: the Iowa Women's Health Study. Cancer Res.
1993;53:4230-7.
10. Kristal AR, Cohen JH, Qu P, Stanford JL. Associations of energy, fat,
calcium, and vitamin D with prostate cancer risk. Cancer Epidemiol
Biomarkers Prev. 2002;11:719-25.
11. Pomerleau J, McKee M, Lobstein T, Knai C. The burden of disease
attributable to nutrition in Europe. Public Health Nutr. 2003;6:453-61.
12. Liebman M, Pelican S, Moore SA, et al. Dietary intake, eating
behavior, and physical activity-related determinants of high body mass
index in rural communities in Wyoming, Montana, and Idaho. Int J Obes
Relat Metab Disord. 2003;27:684-92.
13. Nicklas TA, Yang SJ, Baranowski T, et al. Eating patterns and obesity
in children. The Bogalusa Heart Study. Am J Prev Med. 2003;25:9-16.
14. Freedman DM, Dosemeci M, McGlynn K. Sunlight and mortality from
breast, ovarian, colon, prostate, and non-melanoma skin cancer: a
composite death certificate based case-control study. Occup Environ Med.
2002;59:257-62.
15. Grant WB. An ecologic study of dietary and solar ultraviolet-B links
to breast carcinoma mortality rates. Cancer. 2002;94:272-81.
16. Grant WB. An estimate of premature cancer mortality in the U.S. due to
inadequate doses of solar ultraviolet-B radiation. Cancer. 2002;94:1867-
75.
17. Garland CF. More on preventing skin cancer: sun avoidance will
increase incidence of cancers overall. BMJ. 2003;327:1228.
18. Osborne JE, Hutchinson PE. Vitamin D and systemic cancer: is this
relevant to malignant melanoma? Br J Dermatol. 2002;147:197-213.
19. Holick MF, Photosynthesis of vitamin D in the skin: effect of
environmental and life-style variables, Fed. Proc. 1987;46:1876-82.
20. Devesa SS, Grauman DJ, Blot WJ, et al., Atlas of Cancer Mortality in
the United States, 1950-1994. NIH Publication No. 99-4564, 1999. http://cancer.gov/atlasplus/new.html (accessed December 6, 2003).
Competing interests:
None declared
Competing interests:
No competing interests
07 December 2003
William B. Grant
Atmospheric Sciences, NASA Langley Research Center, but this work is independent of my official duty
12 Sir Francis Wyatt Place, Newport News, VA 23606-3660, USA
Melanoma has a complex etiology that includes UV exposure, skin pigmentation and type, diet, and obesity
The changes in cancer incidence rates in the U.K. from 1991 to 2000
as summarized in the news account by Ferriman (1) and the National
Statistics Office indicated in (1) are very interesting. However, the
statement by Professor Robert Souhami, director of clinical and external
affairs at the charity Cancer Research UK, "The figures highlight the
worrying increase in melanoma, which has one of the fastest growing
incidences of all cancers, despite it being almost entirely preventable.
We need to persuade young people especially to change their attitudes
towards tanning and their behaviour relating to the sun and sunbeds." may
be off the mark. Skin type plays a very important role in the risk of
melanoma, with those with darker skin and the ability to tan at reduced
risk, while those with higher numbers of nevi at increased risk (2,3).
Frequent sunburning is a risk factor for melanoma (4), and should be
avoided. As for sunbed use, a recent study estimated that since 7% of the
U.K. population uses sunbeds, their use could account for 370 of the 6000
annual cases (4). Also, since melanoma generally takes 20-40 years to
develop after exposure to harmful radiation (UV or X-ray), so recent
trends can't be linked to recent changes in tanning practices. Perhaps
increased surveillance has also contributed somewhat to the increased
reported incidence of melanoma, as it has for prostate cancer (1). While
UV exposure is likely involved in a significant fraction of melanoma
incidence in the U.K. (4), there are important interactions between
frequency and duration of UV exposure with skin type, diet, body mass
index, etc.
Overlooked in the press release is the role that diet and obesity
also play in the etiology of melanoma. In a study in Washington State,
Vitamin E obtained from food was inversely related to risk of melanoma
(for highest quartile vs. lowest quartile, age-, education-, and energy
intake-adjusted odds ratio (OR) = 0.34, (95% confidence interval (CI) 0.16
-0.72; p for trend = 0.01). When intake of nutrients from food plus
vitamin and mineral supplements was considered, zinc from food and
supplements was associated with a decreased risk of melanoma (for highest
quartile vs. lowest quartile, adjusted OR = 0.46, 95% CI 0.24-0.91; p for
trend = 0.01) (5). Body mass index is an important risk factor for
melanoma, with one study finding an odds ratio of 1.90 (95% CI 1.10-3.27,
p for trend = 0.02) (5) and another (for males) 2.8 (95% CI 1.5-5.2) (6).
Daily exercise is also a risk reduction factor (6). Given the fact that
Parliament is in the middle of an ongoing series of hearings on obesity,
obesity must be on the rise in the U.K.
To check the obesity/diet hypothesis, we can consider changes in the
incidence of other cancers. Increases were noted for breast, colorectal,
prostate, and testes cancer and leukaemias and lymphomas. Breast cancer
is linked to obesity (7); colon cancer is linked to obesity (8) and
insufficient vitamin E (9); prostate cancer is linked to obesity (10);
lymphoma is linked to obesity (8). 7.8% of the burden of disease in
Europe has been attributed to obesity (11). Thus, unless another reason
can be given for the increase in these cancers, obesity must be on the
rise. To fight obesity, there has to be a concerted effort to reduce the
consumption of junk food, especially that high in sweeteners (added sugar)
(12,13).
Further support for diet and obesity is that solar UVB (280-315 nm)
radiation, through the production of vitamin D, is an important risk
reduction factor for a dozen types of cancer including breast, colorectal,
prostate, and stomach cancer (14-17), and lymphoma (16). Vitamin D may
even be a risk reduction factor for melanoma (18). Thus, if those in the
U.K. were, indeed, getting more UVB radiation in the past 10-20 years, the
vitamin D-sensitive cancer incidence rates should be decreasing with
respect to non-vitamin D-sensitive cancers such as leukaemias (the other,
non-vitamin D-sensitive cancers have specific risk factors such as tobacco
smoke or asbestos fibers). The reduction in stomach cancer may be related
to the use of antibiotics to reduce the risk from H. pylori infection.
In conclusion, those living in the U.K. would be better advised to
seek more, not less, UVB radiation and vitamin D supplementation in order
to reduce the risk of cancer. It is estimated that in the U.S.,
insufficient UVB, the major source of vitamin D in the U.S., (19) accounts
for 45,000 premature deaths and 165,000 avoidable cases annually, compared
with 10,000 deaths due to melanoma and other skin cancer [(16), Grant, in
preparation]. Since the U.K. is farther north than the U.S., and
mortality rates for vitamin D-sensitive cancers are up to twice as high in
the northeast U.S. than in the southwest U.S. (20), the cancer risk due to
insufficient vitamin D is probably much greater than in the U.S., with
perhaps 25% of breast cancer mortality in the U.K. attributable to
insufficient UVB/vitamin D (15, 16).
References
1. Ferriman A. Large increases occur in cancers of skin and prostate. BMJ
2003;327:1306.
2. White E, Kirkpatrick CS, Lee JA. Case-control study of malignant
melanoma in Washington State. I. Constitutional factors and sun exposure.
Am J Epidemiol. 1994;139:857-68.
3. Kennedy C, Bajdik CD, Willemze R, et al. The influence of painful
sunburns and lifetime sun exposure on the risk of actinic keratoses,
seborrheic warts, melanocytic nevi, atypical nevi, and skin cancer. J
Invest Dermatol. 2003;120:1087-93.
4. Diffey BL. A quantitative estimate of melanoma mortality from
ultraviolet A sunbed use in the U.K. Br J Dermatol. 2003;149:578-81.
5. Kirkpatrick CS, White E, Lee JA. Case-control study of malignant
melanoma in Washington State. II. Diet, alcohol, and obesity. Am J
Epidemiol. 1994;139:869-80.
6. Shors AR, Solomon C, McTiernan A, White E. Melanoma risk in relation to
height, weight, and exercise (United States). Cancer Causes Control.
2001;12:599-606.
7. Parker ED, Folsom AR. Intentional weight loss and incidence of obesity-
related cancers: the Iowa Women's Health Study. Int J Obes Relat Metab
Disord. 2003;27:1447-52.
8. Wolk A, Gridley G, Svensson M, et al. A prospective study of obesity
and cancer risk (Sweden). Cancer Causes Control. 2001;12:13-21.
9. Bostick RM, Potter JD, McKenzie DR, et al. Reduced risk of colon cancer
with high intake of vitamin E: the Iowa Women's Health Study. Cancer Res.
1993;53:4230-7.
10. Kristal AR, Cohen JH, Qu P, Stanford JL. Associations of energy, fat,
calcium, and vitamin D with prostate cancer risk. Cancer Epidemiol
Biomarkers Prev. 2002;11:719-25.
11. Pomerleau J, McKee M, Lobstein T, Knai C. The burden of disease
attributable to nutrition in Europe. Public Health Nutr. 2003;6:453-61.
12. Liebman M, Pelican S, Moore SA, et al. Dietary intake, eating
behavior, and physical activity-related determinants of high body mass
index in rural communities in Wyoming, Montana, and Idaho. Int J Obes
Relat Metab Disord. 2003;27:684-92.
13. Nicklas TA, Yang SJ, Baranowski T, et al. Eating patterns and obesity
in children. The Bogalusa Heart Study. Am J Prev Med. 2003;25:9-16.
14. Freedman DM, Dosemeci M, McGlynn K. Sunlight and mortality from
breast, ovarian, colon, prostate, and non-melanoma skin cancer: a
composite death certificate based case-control study. Occup Environ Med.
2002;59:257-62.
15. Grant WB. An ecologic study of dietary and solar ultraviolet-B links
to breast carcinoma mortality rates. Cancer. 2002;94:272-81.
16. Grant WB. An estimate of premature cancer mortality in the U.S. due to
inadequate doses of solar ultraviolet-B radiation. Cancer. 2002;94:1867-
75.
17. Garland CF. More on preventing skin cancer: sun avoidance will
increase incidence of cancers overall. BMJ. 2003;327:1228.
18. Osborne JE, Hutchinson PE. Vitamin D and systemic cancer: is this
relevant to malignant melanoma? Br J Dermatol. 2002;147:197-213.
19. Holick MF, Photosynthesis of vitamin D in the skin: effect of
environmental and life-style variables, Fed. Proc. 1987;46:1876-82.
20. Devesa SS, Grauman DJ, Blot WJ, et al., Atlas of Cancer Mortality in
the United States, 1950-1994. NIH Publication No. 99-4564, 1999.
http://cancer.gov/atlasplus/new.html (accessed December 6, 2003).
Competing interests:
None declared
Competing interests: No competing interests