The mean age of our sample size was 50.3 years old. Mean age was lower in our study compared to Salvatore Sansalone’s (61.5 ± 2.5 years) . Another scarce study of Cui Yu in China reported the median age of 56 years . In Suarez-Ibarrola R.’s study , the mean age of 9 patients undergoing partial penectomy was 57 ± 12.4 years of age at the time of diagnosis. We find that those diagnosed with penile cancer are more frequent in middle-aged men.
Besides poor penile hygiene, men with phimosis have a risk of developing penile cancer; in particular, phimosis is associated with as many as 90% of cases of penile cancer [18, 19]. Of 22 patients with newly diagnosed with penile cancer who were initially treated with partial penectomy, nineteeen patients had phimosis. Prevalence rates of phimosis in male patients was 83.7% in an one-institution study in China of Cui Yu  and 48% in a multi-institutional study of Salvatore Sansalone . The prevalence of phimosis in our study is consistent with Cui Yu’s , showing that male phimosis accounts for a large proportion of patients with penile cancer. However, this figure was significantly lower in Salvator’s study  than ours. In addition to the widely different prevalence of circumcision amongst countries, this may explain that European patients often care a lot about health and are often circumcised at a young age, while Vietnam or China are both Asian countries where no regular phimosis examination since childhood and early circumcision treated uncommonly. Genital wart is also one of the leading causes of penile cancer. In our study, only one patients had a history of genital wart, which then led to penile cancer, while 2 cases in Salvator’s study  were reported.
We followed up 17 out of 22 patients after surgery. These 17 patients had sex with their partners pre-operatively, and postoperatively 13 out of 17 patients had sex after surgery. Of the four patients who did not have sex again after partial penectomy, two patients are over 60 years old. At such an age that is considered elderly, their sexual needs and desires may not be high. Following undergoing partial penectomy, partly due to functional and psychological effects and low sexual desire, it is understandable not to have sex again after surgery. The remaining two patients are all under 40 years old. Despite postoperatively high sexual desire, erectile function and possible vaginal penetratio [16, 17, 20], a psychological sense of inferiority and a reduction in the length of penis makes them less confident to have sex with their partner again. In Cui Yu’s study , 35 out of 43 patients had sex again after surgery. Patients not having sex after surgery are related to age and psychological shame about the penis with partners as well as social prejudices. .
The mean frequency of sexual intercourse within one month after surgery was 3.4 ± 2.1 times, significantly less than before surgery (7.6 ± 2.2 times). According to Ancona’s study  on 14 patients after partial penectomy, the frequency of sexual intercourse within one month after surgery decreased significantly after surgery. Also in Frederico Ramalho Romero’s study , there was also a statistically significant reduction in the frequency of postoperative sexual intercourse.
Among 13 patients having sexual intercourse after surgery, 11 patients did not have erectile dysfunction (IIEF-5 from 22–25 points) (84.62%), mild erectile dysfunction (IIEF-5 from 17–21 points) in 1 patient, mild to moderate erectile dysfunction (IIEF-5 from 12–16 points) and no patient with moderate (IIEF-5 from 8–11 points) to severe erectile (IIEF-5 from 1–7 points). In 2 those with mild and moderate erectile dysfunction, preoperative assessment also showed this condition. In Cui Yu’s study , of 43 study patients, 76.7% of patients did not have erectile dysfunction after surgery. Another study by Ancona  showed that 9 out of 14 patients after partial penectomy had normal erectile function. Thereby, we found that the erectile function is usually relatively good following partial penectomy. The difference between the studies may be because erectile function depends on many other factors such as age, preoperative erection ability, and comorbidities [1, 22].
Vaginal penetration after partial penectomy is frequently possible . According to Romero’s study , penile erection and ejaculation was documented in 55.6% of patients after partial penectomy. Premature ejaculation should also be a matter of concern when this is a common male sexual dysfunction with 30–40% of men affected . We found the majority of patients (11 out of 13 patients) who were without complaints of premature ejaculation after partial penectomy had a total premature ejaculation diagnostic tool (PEDT) score ≤ 8 points. There are 2 patients with total PEDT score of 9–10 points. For the patient with total PEDT score of 9 points, this patient was very worried that the time of ejaculation did not satisfy the partner (3 points), the patient had a loss of premature ejaculation (2 points). For the remaining 3 questions of PEDT, the scores were from 1 to 2 points. We found that most of the patients had no complaints about premature ejaculation. The patients of suspected premature ejaculation with total PEDT scores of 9–10 points had a common feature that their psychology was very worried about their ejaculation status to be able to make their partner satisfied, thereby they felt frustrated when having premature ejaculation. From that, it can be seen the important role of the andrologists and psychologists in providing psychological counseling as well as treatment for these patients. Regarding delayed ejaculation, only one patient experienced delayed ejaculation out of thirteen patients who had sex again after surgery, when another patients had no complaints about delayed ejaculation. The main reason for delayed ejaculation in resuming sexual intercourse appeared to be related to feelings of shame owing to the small penile size and absence of glans penis, and psychological anxiety of pathology of penile cancer. Delayed ejaculation is probably the least studied of male sexual dysfunctions after partial penectomy, with an estimated prevalence of 1–4% of the male population [25–27]. Our study initially contributed to the empirical understood of this sexual dysfunction after partial penectomy.
Regarding decreased sexual desire, among 17 patients in this study, 11 of 17 patients had decreased sex drive postoperatively compared to preoperatively (64.7%). Once interviewing these patients, we found the causes of decreased libido to be psychological anxiety about illness, guilt related to the penis after penectomy, low self-esteem of both the patient and the partner, in addition can be related to age and comorbidities. We also followed up and compared partners’ attitudes toward sex before and after surgery. It can be seen that the partner's frustration and distress in having sex with patients after partial penectomy compared with before partial penectomy is significant different. The most common causes of partner’s frustration and distress in relationships with these patients might be psychological discomfort when having sex with cancer patient, a reduction in the length of penis, and decreased sensations of orgasm and sexual satisfaction. In Ancona’s study  on 14 patients following partial penectomy, 9 patients reported their sexual partners felt uncomfortable and dissatisfied with sex (64.29%). Another study of Romero FR  with a study sample of 18 patients indicated that only 33.3% of partners were satisfied with their sexual relationship after surgery, and 66.7% of partners were dissatisfied and disappointed. Thus, it can be seen that our result was consistent with above studies [20, 21].
We acknowledged relatively small size sample, however, comparable to previous studies. Multivariate models with confounding factors for sexual dysfunction were not reported due to be the statistical significance of present sample size. A larger multicentre sample size is required to perform subgroup analyses of the sexual function of penile carcinoma patient after partial penectomy.