Cancer and Laterality: A Study of The Five Major Paired Organs (UK)
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The human body displays marked asymmetry: paired organs differ bilaterally exerting effects upon cancer incidence and progression. However the factors involved remain contentious. In this large study involving over a quarter of a million cancer patients, we examine the epidemiological correlates of cancer laterality including incidence, stage at diagnosis and survival in the five major paired organs: the breasts, lungs, kidneys, testes and ovaries.
Cancer patients were selected from the Thames Cancer Registry database and age-standardised incidence rates (ASRs), stage distribution at diagnosis and survival rates computed, stratifying appropriately.
Cancer incidence differed significantly by laterality at all sites studied (p<0.01) but substantially in the lung (left–right incidence-rate ratio [IRR] 0.87), breast (IRR 1.07), testis (IRR 0.87) and in ovarian cancer (IRR 0.86). Autopsy data showed strongly coincident left–right organ size ratios (0.87 in the lungs and 0.87 in the testes). Patients with left testicular cancer, right lung cancer and left ovarian cancer showed significantly better survival than those with contralateral disease (p<0.05).
In the lungs and testes, asymmetries in cancer incidence closely coincided with asymmetries in organ size. Our results suggest that tissue mass in these organs is an important contributor to asymmetry in cancer incidence.
KeywordsLaterality Cancer Incidence Stage Survival Asymmetry
- 4.Saxen E, Teppo L, Hakulinen T (1977) Epidemiology of lung cancer in Scandinavia. IARC Sci Publ 217–228Google Scholar
- 9.Esteve J, Benhamou E, Raymond L (1994) Statistical methods in cancer research. In: Esteve J, Benhamou E, Raymond L (eds) Descriptive epidemiology. IARC Sci Publ, Lyon pp 1–302Google Scholar
- 10.Grandmaison GL, Clairand I, Durigon M (2001) Organ weight in 684 adult autopsies: new tables for a Caucasoid population. Forensic Sci Int 15(119):149–154Google Scholar
- 14.Collaborative Group on Hormonal Factors in Breast Cancer (2002) Breast cancer and breastfeeding: collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50302 women with breast cancer and 96973 women without the disease. Lancet 360:187–195Google Scholar
- 15.Ramadhani MK, Elias SG, van Noord PA, Grobbee DE, Peeters PH, Uiterwaal CS (2005) Innate left handedness and risk of breast cancer: case-cohort study. BMJ 15:882–883Google Scholar
- 17.Ansell PE, Bennett V, Bull D, Jackson MB, Pike LA, Pike MC (1992) Cryptorchidism: a prospective study of 7500 consecutive male births, 1984–1988. John Radcliffe Hospital Cryptorchidism Study Group. Arch Dis Child 67:892–899Google Scholar
- 20.Newcomb PA, Storer BE, Longnecker MP, et al. (1994) Lactation and a reduced risk of premenopausal breast cancer. N Engl J Med 13:81–87Google Scholar