Critical appraisal:Byrne J, Mulvihill JJ, Myers MH, Connelly RR, Naughton MD, Krauss MR, et al 1987
Byrne J, Mulvihill JJ, Myers MH, Connelly RR, Naughton MD, Krauss MR, et al. Effects of treatment on fertility in long-term survivors of childhood or adolescent cancer. N Engl J Med 1987 Nov 19;317(21):1315-21 Available from: http://www.ncbi.nlm.nih.gov/pubmed/3683460.
- Are cancer survivors who received cancer treatment less likely than the general population to conceive or give birth after treatment?
Aim to estimate risk of infertility in a "retrospective cohort study survivors" (though really a cross-sectional prevalence/incidence study) of childhood and adolescent cancer and controls
-3270 sibling controls (quasi-matched)
-at age of majority (>21 yrs), and married after Dx. Also excluded pts who were sterile, voluntary infertility, or had a pregnancy before 1st marriage.
relative fertility = association between survivor and control and is equivalent to reltative risk
-in women, 15% survivors were post-menopausal at interview (vs 17% controls) - ave age of menopause 31 vs 36 years.
-survivors who were potentially fertile with sig less likely than controls to report a pregnancy (77% vs 86%; P<0.001)-> crude relative fertility was 0.88. Male survivors had greater fertility deficit than females (relative fertility=0.83 vs 0.94)
-age was not statistically sig factor
-Lower pregnancy rates in survivors - associated with age at marriage and decade of marriage. Those who married 25 or older had a relative fertility of 0.80 (vs 0.90 in those who married <25 years). Those who married <1970 had higher relative fertility (0.95) to >1970 (0.85). These were controlled for in later analyses.
-overall fertility of survivors 15% less than controls (0.85). Ater adjustment, the relative fertility in males slightly lower than crude estimate and remaing sig. in females, adjusted relative fertility was not sig difference to controls.
-differences in pregnancy rates among spouses of male survivors compared with controls apparent after 1 year of marriage. In females only slight differences which diminished over time.
-cancer site - adj relative fertility sig <1 seen in Hodgkin's and male genital system tumors
-least damaging Tx was surgery alone (9% reduction in fertility), RT below diaphragm reduced fertility in both sexes by ~25%, Tx with alkylating agents more harmful than radiation, most damaging was combined Tx with infradiaphragmatic radiation and alkylating agents almost 1/2 of that of controls (relative fertility 0.57). Non-alkylating agents = no deficit (RF=0.98).
-Chemo with alkylating agents, with or without radiation to sites below the diaphragm was assoc with fertility deficit ~60% in men: Alkylating agents along (RF=0.42) vs RT alone above diaphragm (RF=0.89) and below diaphragm (RF = 0.74). RT above diaphragm did not add sig to risk from alkylating agents in men, but in combination below the diaphragm RF=0.38.
-in women, no apparent effect of alkylating agents alone (RF =1.02) and moderate fertility deficit when alkylating agent combined with radiation below the diaphragm (RF=0.81).
-no statistically sig differences between groups in respect to centre, sex or race. Survivors were slightly younger than sibling controls (32.4 yrs vs 33.8 yr
- proxy interviews for 10% survivors and 4% controls
-37% soft tissue sarcomas, thyroid, and tumours of the brain and CNS (roughly equal numbers)
-result only for Tx receive within first 12 months after Dx
-age of Dx dichotomised at 15 years
-relative fertility no affected by income, educational attainment, race, center, self-reported health status, vital status, or other potentially confounding variables (e.g. freq of intercourse, #of marriages, current martial status, use of IUIs, endometriosis or PID, year of birth, or interview type [F2F or phone], proxy, infertility challenges).
|Moderate risk of bias||Comments: Although the source of the populaiton was pretty good, they had some strange eligibility criteria which could result in bias (i.e. married, not had a prior pregnancy etc)|
- Byrne J, Mulvihill JJ, Myers MH, Connelly RR, Naughton MD, Krauss MR, et al. Effects of treatment on fertility in long-term survivors of childhood or adolescent cancer. N Engl J Med 1987 Nov 19;317(21):1315-21 Available from: http://www.ncbi.nlm.nih.gov/pubmed/3683460.
- Assigned to
- Topic area
- Guidelines:COSA:Cancer fertility preservation guidelines/Impact of cancer on fertility
- Clinical question
Section below only relevant for Cancer Council Project Officer