In our study, the proportion of prostate cancer in subjects under 50 years of age was 0.7%. This proportion is similar to that of Alioune et al. in Senegal who found a frequency of 0.45% [14]. This frequency is lower than that of Catalona et al. who found a frequency of 2% of prostate cancer in subjects under 50 years of age [15]. The frequency of prostate cancer in young adults is 4% in Australians and Asians, and 9% and 3% respectively in Caucasians and black Americans [5]. This low frequency in sub-Saharan Africa is underestimated and may be related to the under-medicalization of the health care system, the geographical and financial inaccessibility of health care facilities, the difficulties of diagnosis, the shortage of specialist pathologists and oncologists, and the absence of a program to control cancer in general and prostate cancer in particular.
The average age of our subjects was 45 years. Similar mean ages have been reported by Alioune et al. and Varkarakis et al. of 44.99 and 41.7 years, respectively [14, 16].
It is estimated that 43% of prostate cancers occurring before the age of 50 are hereditary forms [10, 17]. In our series, 41.38% of patients had a family history of prostate cancer, with a statistically significant relationship between the existence of a family history of prostate cancer and the age of onset of the cancers (p-value = 0.03). Rouprêt et al. found a family history of prostate cancer in 33.6% of patients [18].
Clinically, 41.38% of our patients had prostatic hypertrophy. In the series of Alioune et al. and Huang et al. the discovery was incidental in the majority of cases, respectively in 55.9% and 38% [10, 14].
The median PSA level of our patients was 188 ng/ml. This level is much higher than that of Alioune et al. and Varkarakis, which were 26.62 ng/ml and 3.8 ng/ml respectively [14, 16]. Screening for prostate cancer in the presence of elevated serum PSA levels has been used in men over the age of 50 since at least 1992. No medical organization has recommended PSA screening for men in their 30 or 40 s [5].
Histologically, these were all prostatic acinar adenocarcinomas. These adenocarcinomas were predominantly ISUP grade 1 (Gleason score 6) in 65.52%, followed by ISUP grade 5 (Gleason score 9 or 10) in 13.8%. Varkarakis et al. and Huang et al. found a predominance of ISUP grade 2 [10, 16]. Alioune et al. found a predominance of ISUP grade 3 (Gleason score 7 = 4 + 3) [14]. Similar findings were made by Ji et al. who found a predominance of ISUP grade 3, with a statistically significant correlation with age (p-value = 0.002) [19]. Ji et al. report that men aged ≤ 50 years or > 75 years have clinically significant higher grades of prostate cancer compared to patients aged 55–75 years [19].
We did not find a statistically significant relationship between the histoprognostic grade of ISUP and age of cancer occurrence (p-value = 1.06), nor with the existence of a family history of prostate cancers (p-value = 2.21). Similarly, Huang et al. did not find a statistically significant association between histopronostic grade and age (p-value = 0.652) [10]. Bleyer et al. and Ji et al. found a statistically significant relationship between histopronostic grade and age with p-values of 0.043 and 0.002 respectively [5, 19]. Several studies have reported a better survival outcome in men younger than 50 years [5, 11]. However, others have found no significant difference in recurrence, histologic grade, and disease stage [12, 13]. This raises the issue of the age of onset of prostate cancer screening, especially with more and more cases diagnosed around 40 years old [20].
Regarding the pTNM classification, we found 4 cases of stage pT1N0M0 out of the 6 cases specified. Review of the literature indicates that earlier detection of the prostate cancer with low grade and stage disease in young men has a superior disease outcome [7].
Aprikian et al. revealed similar histologic grade and disease stage, between the younger and older population [21].
