The carcinogenic effect of human smegma: an experimental study. I. Preliminary report

Global Pattern and Trends in Penile Cancer Incidence: Population-Based Study

Background

Penile cancer is a relatively rare genital malignancy whose incidence and mortality are rising in many countries.

Objective

This study aims to assess the recent incidence and mortality patterns and incidence trends of penile cancer.

Methods

The age-standardized incidence and mortality rates (ASIR and ASMR, respectively) of penile cancer in 2020 were estimated from the Global Cancer Registries (GLOBOCAN) database. Incidence trends of penile cancer from 1973 to 2012 were assessed in 44 populations from 43 countries using the Cancer Incidence in Five Continents plus (CI5plus) and the Nordic Cancer Registries (NORDCAN) databases. Average annual percentage change was calculated to quantify trends in ASIR using joinpoint regression.

Results

Globally, the estimated ASIR and ASMR of penile cancer were 0.80 (per 100,000) and 0.29 (per 100,000) in 2020, equating to 36,068 new cases and 13,211 deaths in 2020, respectively. There was no significant correlation between the ASIR (P=.05) or ASMR (P=.90) and Human Development Index. In addition, 15 countries saw increasing ASIR for penile cancer, 13 of which were from Europe (United Kingdom, Lithuania, Norway, Estonia, Finland, Sweden, Cyprus, Netherlands, Italy, Croatia, Slovakia, Russia, and the Czech), and 2 from Asia (China and Israel).

Conclusions

Although the developing countries still bear the higher incidence and mortality of penile cancer, the incidence is on the rise in most European countries. To mitigate the disease burden resulting from penile cancer, measures to lower the risk for penile cancers, including improving penile hygiene and male human papillomavirus vaccination, may be warranted.

Does Male Circumcision Reduce Women's Risk of Sexually Transmitted Infections, Cervical Cancer, and Associated Conditions?

Background: Male circumcision (MC) is proven to substantially reduce men's risk of a number of sexually transmitted infections (STIs). We conducted a detailed systematic review of the scientific literature to determine the relationship between MC and risk of STIs and associated conditions in women. Methods: Database searches by "circumcision women" and "circumcision female" identified 68 relevant articles for inclusion. Examination of bibliographies of these yielded 14 further publications. Each was rated for quality using a conventional rating system. Results: Evaluation of the data from the studies retrieved showed that MC is associated with a reduced risk in women of being infected by oncogenic human papillomavirus (HPV) genotypes and of contracting cervical cancer. Data from randomized controlled trials and other studies has confirmed that partner MC reduces women's risk not only of oncogenic HPV, but as well Trichomonas vaginalis, bacterial vaginosis and possibly genital ulcer disease. For herpes simplex virus type 2, Chlamydia trachomatis, Treponema pallidum, human immunodeficiency virus and candidiasis, the evidence is mixed. Male partner MC did not reduce risk of gonorrhea, Mycoplasma genitalium, dysuria or vaginal discharge in women. Conclusion: MC reduces risk of oncogenic HPV genotypes, cervical cancer, T. vaginalis, bacterial vaginosis and possibly genital ulcer disease in women. The reduction in risk of these STIs and cervical cancer adds to the data supporting global efforts to deploy MC as a health-promoting and life-saving public health measure and supplements other STI prevention strategies.

Prognostic factors and biomarkers of penile carcinoma

Penile squamous cell carcinoma (SCC) is a rare malignancy with highest incidence in underdeveloped and developing countries. Oncogenic human papilloma virus (HPV) DNA, mainly types 16 and 18, are found in ∼ 100% of patients with uterine cervix carcinoma. The incidence of this virus in SCC and its variations range from 30.5 to 80%. Despite controversies, contrary to the cervical carcinoma, in the carcinogenesis and disease progression of SCC, HPV-dependent and HPV-independent tumors need to be considered. Lymphadenectomies continue to be the gold standard treatment of lymph node metastases. Undesirable accuracy on staging system methods and high rates of lymphadenectomy complications are the principal objections to these surgical procedures; therefore, the main issue in patients with SCC is to know who should or should not undergo lymphadenectomy. The search for primary tumor anatomopathological and biomarker risk factors for lymph node metastases, such as has occurred in other tumors, may be an important tool to select lymphadenectomies candidates better. Histological subtypes, tumor grade, growth pattern, tumor thickness, lymphatic embolization by neoplasic cells and depth of infiltration have been reported as important prognostic factors for lymph node metastases. In our series, lymphatic vascular permeation, palpable lymph node after primary tumor control (cN stage), pattern of invasion, p53 and PCNA immunoreactivity are independent lymph node metastases risk factors in the multivariate model. It is strongly recommended that patients be concentrated in specialized centers or cancer hospitals and multi-centric prospective studies carried out on tumor markers in this rare disease, in order to stage better lymph node disease and avoid unnecessary surgeries with high morbidity rates.

Induction of Cancer of the Cervix Uteri in Relation to the Oestrus Cycle

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The Strong Protective Effect of Circumcision against Cancer of the Penis

Male circumcision protects against cancer of the penis, the invasive form of which is a devastating disease confined almost exclusively to uncircumcised men. Major etiological factors are phimosis, balanitis, and high-risk types of human papillomavirus (HPV), which are more prevalent in the glans penis and coronal sulcus covered by the foreskin, as well as on the penile shaft, of uncircumcised men. Circumcised men clear HPV infections more quickly. Phimosis (a constricted foreskin opening impeding the passage of urine) is confined to uncircumcised men, in whom balanitis (affecting 10%) is more common than in circumcised men. Each is strongly associated with risk of penile cancer. These findings have led to calls for promotion of male circumcision, especially in infancy, to help reduce the global burden of penile cancer. Even more relevant globally is protection from cervical cancer, which is 10-times more common, being much higher in women with uncircumcised male partners. Male circumcision also provides indirect protection against various other infections in women, along with direct protection for men from a number of genital tract infections, including HIV. Given that adverse consequences of medical male circumcision, especially when performed in infancy, are rare, this simple prophylactic procedure should be promoted.

A rare case of penile cancer in situ metastasizing to lymph nodes

Penile carcinoma in situ, or Queyrat's erythroplasia, is a rare condition of the glans penis. This lesion has been associated with invasive squamous cell carcinoma; however, metastasis without an invasive component is extremely rare. There have only been 2 documented cases with metachronous metastases. We report a third case in which metastases were diagnosed at presentation. The patient was a 51-year-old man who presented with a glans penile lesion and bilateral inguinal masses later determined to be carcinoma in situ with metastases to the inguinal and pelvic lymph nodes. He subsequently underwent a partial penectomy and lymphadenectomy followed by adjuvant chemotherapy and radiation. This case is discussed, along with a brief review of the literature.

Why circumcision is a biomedical imperative for the 21(st) century

Circumcision of males represents a surgical "vaccine" against a wide variety of infections, adverse medical conditions and potentially fatal diseases over their lifetime, and also protects their sexual partners. In experienced hands, this common, inexpensive procedure is very safe, can be pain-free and can be performed at any age. The benefits vastly outweigh risks. The enormous public health benefits include protection from urinary tract infections, sexually transmitted HIV, HPV, syphilis and chancroid, penile and prostate cancer, phimosis, thrush, and inflammatory dermatoses. In women circumcision of the male partner provides substantial protection from cervical cancer and chlamydia. Circumcision has socio-sexual benefits and reduces sexual problems with age. It has no adverse effect on penile sensitivity, function, or sensation during sexual arousal. Most women prefer the circumcised penis for appearance, hygiene and sex. Given the convincing epidemiological evidence and biological support, routine circumcision should be highly recommended by all health professionals.

The carcinogenicity of smegma: debunking a myth

BACKGROUND

Smegma is widely believed to cause penile, cervical and prostate cancer. This nearly ubiquitous myth continues to permeate the medical literature despite a lack of valid supportive evidence.

METHODS

A historical perspective of medical ideas pertaining to smegma is provided, and the original studies in both animals and humans are reanalysed using the appropriate statistical methods.

RESULTS

Evidence supporting the role of smegma as a carcinogen is found wanting.

CONCLUSIONS

Assertions that smegma is carcinogenic cannot be justified on scientific grounds.

Treatment of penile carcinoma: To cut or not to cut?

PURPOSE

The aim of this study was to assess the outcome in patients with penile cancer.

METHODS AND MATERIALS

A total of 60 patients with penile carcinoma were included. Of the patients, 45 (n = 27) underwent surgery, and 51 underwent definitive (n = 29) or postoperative (n = 22) radiotherapy (RT). Median follow-up was 62 months.

RESULTS

Median time to locoregional relapse was 14 months. Local failure was observed in 3 of 23 patients (13%) treated with surgery with or without postoperative RT vs. in 19 of 33 patients (56%) given organ-sparing treatment (p = 0.0008). Of 22 local failures, 16 (73%) were salvaged with surgery. Of the 33 patients treated with definitive RT (n = 29) and the 4 patients refusing RT after excisional biopsy, local control was obtained with organ preservation in 13 (39%). In the remaining 20, 4 patients with local failure underwent salvage conservatively, resulting in an ultimate penis preservation rate of 17 of 33 (52%) patients treated with definitive RT. The 5-year and 10-year probability of surviving with an intact penis was 43% and 26%, respectively. There was no survival difference between the patients treated with definitive RT and primary surgery (56% vs. 53%; p = 0.16). In multivariate analysis, independent factors influencing survival were N-classification and pathologic grade. Surgery was the only independent predictor for better local control.

CONCLUSION

Based on our study findings, in patients with penile cancer, local control is superior with surgery. However, there is no difference in survival between patients treated with surgery and those treated with definitive RT, with 52% organ preservation.

Penile cancer

Penile cancer, while relatively rare in the western world, remains a disease with severe morbidity and mortality, not to mention significant psychological ramifications. Furthermore, the disease is observed with dramatically increased incidence in other parts of the world. A review of the literature has shown that the overwhelming majority of penile cancers are in situ or invasive squamous cell carcinomas, including a well-differentiated variant, verrucous carcinoma. Important predisposing factors are lack of circumcision, human papillomavirus infections, and penile lichen sclerosus, although other factors have occasionally been reported as well. Prevention, careful monitoring of patients at risk, and early diagnosis are essential to reduce the incidence of penile carcinoma and to provide a definitive cure. Public health measures, such as prophylactic use of circumcision, have proved successful but are controversial. Also, no standard therapeutic guidelines as to the best treatment strategy according to different stages, including efficacy of conservative nonsurgical modalities and indications for lymph nodal dissection, are available so far. It is common opinion that penile cancer is an emerging problem that deserves further investigations, and physicians, especially dermatologists, should be aware of this issue.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with penile carcinoma, its risk factors, its clinical and histologic presentation, and the treatments currently available for its management.

Radiation therapy alone or combined surgery and radiation therapy in squamous-cell carcinoma of the penis?

To assess the prognostic factors and the outcome in patients with squamous-cell carcinoma of the penis, a retrospective review of 41 consecutive patients with non-metastatic invasive carcinoma of the penis, treated between 1962 and 1994, was performed. The median age was 59 years (range: 35-76 years). According to the International Union Against Cancer (UICC) 1997 classification, there were 12 (29%) T1, 24 (59%) T2, 4 (10%) T3 and 1 TX (2%) tumours. The N-classification was distributed as follows: 29 (71%) patients with N0, 8 (20%) with N1, 3 (7%) with N2 and 1 (2%) with N3. Forty-four per cent (n=18) of the patients underwent surgery: partial penectomy with (n=4) or without (n=12) lymph node dissection, or total penectomy with (n=1) or without (n=1) lymph node dissection. 23 patients were treated with radiation therapy alone, and all but 4 of the patients who were operated upon received postoperative radiation therapy (n=14). The median follow-up period was 70 months (range 20-331 months). In a median period of 12 months (range 5-139 months), 63% (n=26) of the patients relapsed (local in 18, locoregional in 2, regional in 3 and distant in 3). Local failure (stump in the operated patients, and the tumour bed in those treated with primary radiation therapy) was observed in 4 out of 16 (25%) patients treated with partial penectomy +/-postoperative radiotherapy versus 14 out of 23 (61%) treated with primary radiotherapy (P=0.06). 15 (83%) out of 18 local failures were successfully salvaged with surgery. In all patients, 5- and 10-year survival rates were 57% (95% confidence interval (CI), 41-73%) and 38% (95% CI, 21-55%), respectively. The 5-year local and locoregional rates were 57% (95% CI, 41-73%) and 48% (95% CI, 32-64%), respectively. In patients treated with primary radiotherapy, 5- and 10-year probabilities of surviving with penis preservation were 36% (95% CI, 22-50%) and 18% (95% CI, 2-34%), respectively. In multivariate analyses, survival was significantly influenced by the N-classification, and surgery was the only independent factor predicting the locoregional control. We conclude that, in patients with squamous-cell carcinoma of the penis, local control is better in patients treated with surgery. However, there seems to be no difference in terms of survival between patients treated by surgery and those treated by primary radiotherapy +/-salvage surgery, with 39% having organ preservation.

Neoplasia of the male reproductive tract

Genital neoplasms in the male horse are relatively uncommon. Squamous cell carcinomas and squamous papillomas are the most commonly diagnosed neoplasms of the penis and prepuce. Geldings appear to be overrepresented for these types of neoplasms, and accumulation of smegma may be a contributing factor. Early diagnosis and treatment are essential for salvaging these organs before lesions become excessively large and invasive or are allowed to metastasize. Newer treatment modalities such as 5-fluorouracil appear to be promising alternatives to surgical excision. Although generally considered to be uncommon, testicular tumors may occur more frequently than previously thought and have the potential for devastating effects on stallion fertility. Cryptorchidism appears to play a role in the development of equine testicular tumors, especially teratomas. Seminoma is by far the most common testicular tumor of the mature stallion. Seminomas are rapidly growing tumors with a greater potential to metastasize in the horse than in other domestic species. Leydig cell and Sertoli cell tumors have been reported but are relatively rare in the stallion. Orchiectomy is the standard treatment for most testicular tumors. In certain circumstances, however, such as neoplasia occurring in the only functional testis, local cryotherapy of testicular tumors may prolong the breeding career of an affected stallion.

Squamous cell carcinoma of the penis

Penile tumors, although not frequent, represent a difficult diagnostic and therapeutic challenge. Of the malignant penile neoplasms, the most frequent is penile carcinoma, which includes squamous cell carcinoma and its well-differentiated variant, verrucous carcinoma. Current concepts about classification, epidemiology, pathogenesis, histopathology, diagnosis, staging, prognosis, and treatment are presented.

Human papillomavirus 16 exhibits a similar integration pattern in primary squamous cell carcinoma of the penis and in its metastasis

BACKGROUND

Human papillomaviruses (HPV) are among the most common causes of sexually transmitted viral infections in the United States, and HPV types 16, 18, and others have been strongly linked with the development of cervical cancer. DNA from these oncogenic HPV types also has been detected in biopsy specimens of penile intraepithelial and invasive neoplasms, indicating a causal role of these viruses in the malignant transformation of these tissue.

METHODS

Southern blot analysis and two-dimensional gel electrophoresis were used to investigate the presence and physical state of HPV in a patient with metastatic penile carcinoma.

RESULTS

The presence of HPV 16 DNA integrated into the host's genome was documented in a primary penile squamous cell carcinoma and its lymph node metastasis.

CONCLUSIONS

The identical restriction endonuclease cleavage patterns for HPV 16 in both the primary tumor and its lymph node metastasis indicate that both tumors arose from a single clonal event. This finding provides evidence of a causal role of HPV in squamous cell carcinoma of male genitalia.

Future trends in cervical cancer

The identification of the close association of certain types of human papillomavirus with the development of cervical cancer should lead to an extensive revision of appropriate health policies. Having taken into account the drawbacks inherent in the existing data (stemming from the use of varying nomenclature, diagnostic methods and reliability, registration and screening practices) it is possible to conclude that the incidence of HPV infections, all premalignant and malignant stages of cervical cancer are, or will soon be, increasing in several countries. This rate of increase is fastest for the younger age groups and is despite the introduction of various forms of screening. These trends therefore indicate an urgent need to adopt policies to avert an unnecessary increase in fatalities due to cervical cancer. It is therefore recommended to: (1) establish a routine diagnostic method which can identify either the type of HPV present or the lesions which are progressing; (2) determine the incidence of HPV infections in the general population; (3) disseminate to medical personnel, teachers, and other members of society existing knowledge concerning the dangers associated with this virus and relevant to preventing its further spread; (4) introduce an effective population screening campaign for all sexually active women, preferably involving a yearly examination at a colposcopy clinic; (5) intensify basic and applied HPV research, especially that which could lead to a deeper understanding of viral transmission and infection, identification of cofactors which promote cervical lesion progression, or to the production of a vaccine.

Penile cancer: is there an epidemiological role for smoking and sexual behaviour?

A retrospective study was carried out to determine whether penile cancer, like cervical cancer, was associated with smoking and sexual behaviour. Altogether 244 men with penile cancer and 232 matched controls completed a questionnaire by post or telephone. Data on marital state, socioeconomic group, occupation, history of phimosis and balanitis, sexual behaviour, and smoking were obtained. The results of statistical analyses confirmed that phimosis and balanitis were risk factors for penile cancer, but there was no epidemiological evidence for it being a sexually transmitted disease. Smoking was a risk factor with a dose-response relation and remained associated with penile cancer even after adjustment for confounding factors. Penile cancer is associated with smoking independently of phimosis; treatment of phimosis alone does not remove the risk caused by smoking.

Venereal factors in human cervical cancer: evidence from marital clusters

All Caucasian women in a large Eastern city who developed pathologically confirmed cervical cancer between 1950 and 1969 are being prospectively followed in an epidemiological test of the venereal hypothesis of cervical carcinogenesis. We are attempting to identify all men who were married to these probands at any time prior to the date of their cancer diagnosis. The ultimate objective is the identification of all the other wives of the proband husbands in order that their risk of cervical cancer be assessed. A random sample of control wives similar to the other wives in age, race, date and place of marriage as well as prior marital status is also being followed. To date, a total of 1,087 other wives and 659 control wives has been fully traced. Cervical cancer or carcinoma in situ was detected in 29 (2.7%) of the other wives and in seven (1.1%) of the control wives. A total of 14.0% of the other wives had either cervical cancer or a cervical cytological specimen which was other than normal. The corresponding statistic for the control wives was 8.0%. These differences in the prevalence of cervical cancer and of non-normal cervical cytology are statistically significant. In the course of this investigation so far, we have identified 29 "marital clusters" of cervical cancer in which two women married to the same man have all developed cervical neoplasms. The observed number of 29 clusters may be compared with an expected number of 11.6. This investigation, as yet incomplete, offers confirmatory evidence of the possible role of venereal factors in the pathogenesis of human cervical neoplasia. While the genital herpesvirus is the likeliest candidate, other venereal elements might also be involved.

Prevalence rates of uterine cervical carcinoma in situ for women using the diaphragm or contraceptive oral steroids

Study of the prevalence rates of uterine cervical carcinoma in situ among women attending centres of Planned Parenthood of New York City, Inc., showed a small but statistically significant difference between the population choosing and using the diaphragm and the population choosing and using oral steroids for contraception. This can be attributed either to a decreased prevalence rate for women using the diaphragm or to an increased rate for women using oral steroids. The reason for the difference is not apparent from these data.