Table 1.

Systemic review of the included studies in meta-analysis.

Author	Country	Study design	Male infertility Definition	Characteristics of men with infertility	Characteristics of men without infertility	Follow-up period	Control of confounder variables	Outcome of interest	Main findings
Eisenberg et al. (19)	USA	Retrospective Cohort	Men with azoospermia	N = 451 Age = 35.5 (8.3) BMI = NM	N = 1787 Age = 35.8 (6.9) BMI = NM	6.7 years	Adjusted for age and year of evaluation	All cancers	Compared to the general population, men with infertility had a higher risk of cancer. Stratifying by the azoospermia status showed that azoospermic men had an elevated risk of cancer, and those without azoospermia had a trend toward a higher rate of cancer
Eisenberg et al. (20)	USA	Retrospective Cohort	ICD-9	N = 76083 Age = 35.08 (5.89) BMI = NM	N = 760830 Age = NM BMI = NM	277703 person-years	Matched on age and follow-up time	All and individual cancers of testicular, prostate, melanoma, kidney, upper aerodigestive, stomach, colon and rectum, liver and gallbladder, pancreas, urinary bladder, breast and lung, esophagus, leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, thyroid, nervous system	Men with infertility had a higher risk of testicular cancer, non-Hodgkin lymphoma and all cancers than the counterparts men without infertility
Elenkov et al. (11)	Sweden	Prospective population-based cohort	Being childless	N = 2134 Age = 48.9 (4.1) BMI = 25.3 (3.8)	N = 9209 Age = 48.7 (3.9) BMI = 25 (3.2)	Up to 42 years	Adjusted for smoking, education and marital status, BMI, high blood pressure	Prostate cancer	Childless men had the higher risk of prostate cancer-related mortality compared to men with children. However, the prostate cancer incidence did not differ between them
Hanson et al. (21)	USA	Retrospective cohort	All men presenting for infertility that underwent semen analysis	N = 20433 Age = NM BMI = NM	N = 20433 Age = NM BMI = NM	On average for 7.3 years with a maximum of 18 years	Matched on age and birth year	All cancers, and prostate, testicular, melanoma, and other cancers	Men with semen analysis had an increased risk of testicular cancer compared to men without infertility. There were no significant differences in the cancer risk for the other common sites or the overall risk of cancer
Walsh et al. (22)	USA	Retrospective cohort	Infertile men with abnormal semen WHO-1999 criteria	N = 4549 Age = 38.1 (7.4) BMI = NM	N = 14557 Age = 36.4 (6.4) BMI = NM	Mean (SD): 11.4 (2.9) years	Matched on age	Testicular Cancer	Men with infertility had an increased risk of subsequently developing testicular cancer
Walsh et al. (23)	USA	Retrospective cohort	Infertile men with abnormal semen WHO-1999 criteria	N = 4549 Age = 38.1 (7.4) BMI = NM	N = 14557 Age = 36.4 (6.4) BMI = NM	Mean (SD): 11.4 (2.9) years	Matched on age and geography	Prostate Cancer	Men with male infertility were found to have an increased risk of subsequently developing high-grade prostate cancer
Jacobsen et al. (24)	Denmark	Retrospective cohort	All men in couples with fertility problems who had impaired semen analysis	N = 29177 Age = NM BMI = NM	N = 300000 Age = NM BMI = NM	NM	NM	All cancers, and testicular, peritoneum and other cancers	Men with infertility were more likely to develop testicular and peritoneum and other digestive organs cancer than other men
Al-Jebari et al. (25)	Sweden	Retrospective cohort	All men used assisted reproductive techniques including IVF and ICSI	N = 35500 Age = NM BMI = NM	N = 1145990 Age = NM BMI = NM	14389198 person years	Adjusted for fathers’ age at childbirth, father’s education level	Prostate cancer	Men who became fathers through assisted reproduction had a statistically significantly increased risk of prostate cancer compared with men who conceived naturally

ICD, International Statistical Classification of Diseases; 9th edition; BMI, Body Mass Index; IVF, In vitro fertilization; ICSI, Intracytoplasmic sperm injection; NM, Not mentioned.