A review of the aetiology of squamous cell carcinoma of the conjunctiva

Ocular surface squamous neoplasia in Northern Thailand: a 16-year review

Purpose

To evaluate clinical characteristics, treatments, and outcomes in patients with ocular surface squamous neoplasia (OSSN) at a tertiary center in Northern Thailand.

Methods

Patients diagnosed with either corneal-conjunctival intraepithelial neoplasia (CIN) or squamous cell carcinoma (SCC) from May 2000 to December 2015, were recruited. The patients’ demographics, symptoms, clinical characteristics, cytopathology, treatments, and outcomes were reviewed.

Results

Overall 171 eyes from 168 patients, 92 eyes were CIN and 79 eyes were SCC. Males were affected in 65.5%. The mean age was 58.8 ± 16.8 (29–99) years. In most cases (60.3%), the tumors were located at the limbus. The most common clinical characteristic was papilliform appearance (46.2%). Human immunodeficiency virus (HIV) infection was found in 37 (22.0%) patients with a mean age of 40.5 ± 7.7 years. The treatments and outcomes were evaluated in 136 eyes whose main initial treatment was wide excision with adjunctive cryotherapy (47.8%), followed by topical mitomycin C (30.9%). The mean follow-up time after treatment was 20.8 ± 2.2 (3–110) months and the recurrence occurred in 18 eyes (13.2%) during the follow-up period. The mean recurrence-free time (months) for CIN was significantly longer than that of SCC (81.3 ± 10.0 [95%CI 61.5 – 101.1] vs 33.2 ± 4.6 [95%CI 24.0 – 42.3], p = 0.030). SCC was the only significant risk factor that influences the recurrence of the tumors with the adjusted hazard ratio of 5.69 (p = 0.005).

Conclusion

OSSN in Northern Thailand usually involved a limbal area and presented as a papilliform mass. HIV infection should be suspected in young patients. CIN had better outcomes after treatments than invasive SCC.

Conjunctival cancer in people living with HIV

PURPOSE OF REVIEW

Historically, conjunctival cancer has been associated with HIV particularly in sub-Saharan Africa. The human papilloma virus (HPV) has been implicated as a potential causative agent without conclusive evidence. This review covers recent evidence of the epidemiology, diagnosis and treatment of conjunctival cancer in people living with HIV (PLWH).

RECENT FINDINGS

HIV infection has been attributed to 33% of squamous cell carcinoma of the conjunctiva in sub-Saharan Africa. Although clear evidence of the effect of immunodeficiency on conjunctival cancer risk has been demonstrated, the role of HPV on conjunctival cancer development is still unclear. Biomarkers such as the p16 protein are not always indicative of HPV infection. The Epstein-Barr virus (EBV) might potentially be another infectious agent of interest in the development of conjunctival cancer. There is some evidence of increased conjunctival cancer recurrence post treatment as well as increased probability of metastasis in PLWH.

SUMMARY

Immunodeficiency increases the risk of conjunctival cancer in PLWH. Symptomatic screening of conjunctival cancer in PLWH should be encouraged. Research on HPV involvement should remain a priority and EBV considered as another etiologic agent of interest. More studies on treatment modalities in PLWH should be considered.

Detection of a large spectrum of viral infections in conjunctival premalignant and malignant lesions

To study the interaction between HIV and other carcinogenic infections in conjunctival squamous cell carcinoma (SCC), we evaluated the presence of a broad spectrum of human viruses in conjunctiva specimens. Beta Human papillomavirus (HPV; n = 46), gamma HPV (n = 52), polyomaviruses (n = 12) and herpes viruses (n = 3) was determined in DNA extracted from 67 neoplastic and 55 non-neoplastic conjunctival tissues of HIV-positive and HIV negative subjects by Luminex-based assays. Next-generation sequencing (NGS) was also used to further characterize the presence of cutaneous HPVs. Detection of beta-2 HPV infections was associated with the risk of neoplasia (adjusted odds ratio [aOR] 3.0; 95% confidence interval [CI] 1.3-6.8), regardless of HIV status (HIV positive, aOR 2.6, 95% CI 0.9-7.7; HIV negative, aOR 3.5, 95% CI 0.9-14.4). EBV was strongly associated with the risk of neoplasia (aOR 12.0, 95% CI 4.3-33.5; P < .01) mainly in HIV individuals (HIV positive, aOR 57.5; 95% CI: 10.1-327.1; HIV negative aOR 2.6; 95% CI: 0.2-34.7). NGS allowed to identify 13 putative novel HPVs in cases and controls. Our findings suggest a role of beta HPV types and EBV, in conjunctival SCC. However, additional studies of viral expression in tumor tissue are required to confirm the causal association.

Spectrum of conjunctival tumours in a Spanish series: A review of 462 cases

INTRODUCTION

To report the spectrum and frequency of conjunctiva tumours in an ocular oncology unit analysing the clinical profile of benign, precancerous and malignant conjunctival lesions.

METHODS

A retrospective case series of 462 consecutive patients diagnosed at the Ocular Oncology Unit of the University Hospital of Valladolid from 1992 to 2017.

RESULTS

Among 462 consecutive patients, the tumour was classified as melanocytic in 252 (54.5%) and non-melanocytic in 210 (45.5). Two hundred forty-eight males (mean age 51.63 (SD = 23.20)) and 214 females (mean age 48.27 (SD = 21.77)) were included. Mean patient age at diagnosis was 50.07 years (range = 1-92 years). The majority of tumours were benign (n = 307 (66.5%)) followed by precancerous (n = 103 (22.3%)) and finally by malignant ones (n = 52 (11.3%)). Benign lesions were predominantly found in younger individuals rather than premalignant (p < 0.05) and malignant ones (p < 0.05). Most of the melanocytic lesions were benign (88.5%), most epithelial ones were precancerous (61.4%) and most lymphoid lesions were malignant (56.3%). Tumours involving one or four quadrants of the ocular surface usually were benign, unlike tumours involving three quadrants that were malignant (16 (48.5%) p < 0.05). The majority of benign lesions were detected on females (n = 163 (53.1%)) by routine examination (n = 178 (86.4%)). However, main complaint in malignant tumours was the growth of the lesion (n = 39 (76.5%)).

CONCLUSION

Most of the conjunctival tumours were melanocytic, mostly benign, closely followed by those of epithelial origin, with a predominance of precancerous lesions. Melanocytic, epithelial and lymphoid tumours accounted for over 90% of cases. A trend was identified with benign lesions being found in younger female patients on routine examination.

Telomerase promoter mutations in human immunodeficiency virus-related conjunctiva neoplasia

BACKGROUND

Squamous cell carcinoma (SCC) of the conjunctiva is a common cancer in Africa mainly associated with solar ultraviolet (UV) exposure and human immunodeficiency virus (HIV) infection. We analyzed the role of HIV on the occurrence of telomerase reverse transcriptase (TERT) promoter mutations among a cohort of conjunctiva neoplasia Ugandan patients.

METHODS

Telomerase reverse transcriptase promoter mutations were searched in 72 conjunctiva neoplasia cases, comprising SCC and intraepithelial neoplasia grade 1-3 (CIN1-3), as well as in 53 conjunctiva normal tissues and in 24 HIV-related Kaposi sarcoma.

RESULTS

The average prevalence of TERT promoter mutations in conjunctiva neoplasia was 31.9%. The mutation rates were significantly higher in HIV-positive (31.8% of CIN1 and CIN2, 46.2% of CIN3 and SCC,) than HIV-negative patients (22.2% of CIN1 and CIN2, 13.3% of CIN3 and SCC). Such mutations were rarely identified among HIV-positive conjunctiva controls (3.6%) and never in Kaposi sarcoma lesions. The most frequent variations were the hot spots - 124G>A and - 146G>A and tandem transitions - 124_125GG>AA and - 138_139GG>AA.

CONCLUSIONS

Telomerase reverse transcriptase promoter mutations are early events in conjunctival neoplasia and could be used for timely diagnosis of conjunctiva tumours. The high frequency of UV-signatures in HIV-positive conjunctiva lesions suggests an additive effect of the virus to UV-related mutagenesis.

Ocular surface squamous neoplasia in HIV-infected patients: current perspectives

Ocular surface squamous neoplasia (OSSN) refers to a spectrum of conjunctival and corneal epithelial tumors including dysplasia, carcinoma in situ, and invasive carcinoma. In this article, we discuss the current perspectives of OSSN associated with HIV infection, focusing mainly on the epidemiology, pathophysiology, clinical manifestations, diagnosis, and treatment of these tumors in patients with HIV. Upsurge in the incidence of OSSN with the HIV pandemic most severely affected sub-Saharan Africa, due to associated risk factors, such as human papilloma virus and solar ultraviolet exposure. OSSN has been reported as the first presenting sign of HIV/AIDS in 26%-86% cases, and seropositivity is noted in 38%-92% OSSN patients. Mean age at presentation of OSSN has dropped to the third to fourth decade in HIV-positive patients in developing countries. HIV-infected patients reveal large aggressive tumors, higher-grade malignancy, higher incidence of corneal, scleral, and orbital invasion, advanced-stage T4 tumors, higher need for extended enucleation/exenteration, and increased risk of tumor recurrence. Current management of OSSN in HIV-positive individuals is based on standard treatment guidelines described for OSSN in the general population, as there is little information available about various treatment modalities or their outcomes in patients with HIV. OSSN can occur at any time in the disease course of HIV/AIDS, and no significant trend has been discovered between CD4 count and grade of OSSN. Furthermore, the effect of highly active antiretroviral therapy on OSSN is controversial. The current recommendation is to conduct HIV screening in all cases presenting with OSSN to rule out undiagnosed HIV infection. Patient counseling is crucial, with emphasis on regular follow-up to address high recurrence rates and early presentation to an ophthalmologist for of any symptoms in the unaffected eye. Effective evidence-based interventions are needed to allow early diagnosis and treatment, as well as prevention of the disease.

The biology of beta human papillomaviruses

The beta genus comprises more than 50 beta human papillomavirus (HPV) types that are suspected to be involved, together with ultraviolet (UV) irradiation, in the development of non-melanoma skin cancer (NMSC), the most common form of human cancer. Two members of the genus beta, HPV5 and HPV8, were first identified in patients with a genetic disorder, epidermodysplasia verruciformis (EV), that confers high susceptibility to beta HPV infection and NMSC development. The fact that organ transplant recipients (OTRs) with an impaired immune system have an elevated risk of NMSC raised the hypothesis that beta HPV types may also be involved in skin carcinogenesis in non-EV patients. Epidemiological studies have shown that serological and viral DNA markers are weakly, but significantly, associated with history of NMSC in OTRs and the general population. Functional studies on mucosal high-risk (HR) HPV types have clearly demonstrated that the products of two early genes, E6 and E7, are the main viral oncoproteins, which are able to deregulate events closely linked to transformation, such as cell cycle progression and apoptosis. Studies on a small number of beta HPV types have shown that their E6 and E7 oncoproteins also have the ability to interfere with the regulation of key pathways/events associated with cellular transformation. However, the initial functional data indicate that the molecular mechanisms leading to cellular transformation are different from those of mucosal HR HPV types. Beta HPV types may act only at early stages of carcinogenesis, by potentiating the deleterious effects of other carcinogens, such as UV radiation.

Risk factors for ocular surface squamous neoplasia in Kenya: a case-control study

OBJECTIVE

To determine modifiable risk factors of ocular surface squamous neoplasia (OSSN) in Kenya using disease-free controls.

METHODS

Adults with conjunctival lesions were recruited at four eye care centres in Kenya and underwent excision biopsy. An equal number of controls having surgery for conditions not affecting the conjunctiva and unrelated to ultraviolet light were group-matched to cases by age group, sex and eye care centre. Associations of risk factors with OSSN were evaluated using multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Continuous variables were compared using the t-test or the Wilcoxon-Mann-Whitney U-test depending on their distribution.

RESULTS

A total of 131 cases and 131 controls were recruited. About two-thirds of participants were female, and the mean age of cases and controls was 42.1 years and 43.3 years, respectively. Risk factors for OSSN were HIV infection without antiretroviral therapy (ART) use (OR = 48.42; 95% CI: 7.73-303.31) and with ART use (OR = 19.16; 95% CI: 6.60-55.57), longer duration of exposure to the sun in the main occupation (6.9 h/day vs. 4.6 h/day, OR = 1.24; 95% CI: 1.10-1.40) and a history of allergic conjunctivitis (OR = 74.61; 95% CI: 8.08-688.91). Wearing hats was protective (OR = 0.22; 95% CI: 0.07-0.63).

CONCLUSION

Measures to prevent and control HIV, reduce sun exposure such as wearing hats and control allergic conjunctivitis are recommended.

Solar ultraviolet radiation in Africa: a systematic review and critical evaluation of the health risks and use of photoprotection

The majority of the African continent experiences high solar UVB radiation throughout the year. The adverse consequences of this on the health of populations living in Africa are reviewed.

Correlation of EGFR, pEGFR and p16INK4 expressions and high risk HPV infection in HIV/AIDS-related squamous cell carcinoma of conjunctiva

Background

Squamous cell carcinoma of conjunctiva has increased tenfold in the era of HIV/AIDS. The disease pattern has also changed in Africa, affecting young persons, with peak age-specific incidence of 30-39 years, similar to that of Kaposi sarcoma, a well known HIV/AIDS defining neoplasm. In addition, the disease has assumed more aggressive clinical course. The contributing role of exposure to high risk HPV in the development of SCCC is still emerging.

Objective

The present study aimed to investigate if immunohistochemical expressions of EGFR, pEGFR and p16, could predict infection with high risk HPV in HIV-related SCCC.

Methods

FFPE tissue blocks of fifty-eight cases diagnosed on hematoxylin and eosin with SCCC between 2005-2011, and subsequently confirmed from medical records to be HIV positive at the department of human pathology, UoN/KNH, were used for the study. Immunohistochemistry was performed to assess the expressions of p16INK4A, EGFR and pEGFR. This was followed with semi-nested PCR based detection and sequencing of HPV genotypes. The sequences were compared with the GenBank database, and data analyzed for significant statistical correlations using SPSS 16.0. Ethical approval to conduct the study was obtained from KNH-ERC.

Results

Out of the fifty-eight cases of SCCC analyzed, twenty-nine (50%) had well differentiated (grade 1), twenty one (36.2%) moderately differentiated (grade 2) while eight (13.8%) had poorly differentiated (grade 3) tumours. Immunohistochemistry assay was done in all the fifty eight studied cases, of which thirty nine cases (67.2%) were positive for p16INK4A staining, forty eight cases (82.8%) for EGFR and fifty one cases (87.9%) showed positivity for p-EGFR. HPV DNA was detected in 4 out of 40 SCCC cases (10%) in which PCR was performed, with HPV16 being the only HPV sub-type detected. Significant statistical association was found between HPV detection and p16INK4 (p=0.000, at 99% C.I) and EGFR (p=0.028, at 95% C.I) expressions, but not pEGFR. In addition, the expressions of these biomarkers did not show any significant association with tumor grades.

Conclusion

This study points to an association of high risk HPV with over expressions of p16INK4A and EGFR proteins in AIDS-associated SCCC.

[Conjunctival squamous cell carcinoma: paradoxical response to interferon eyedrops]

CASE REPORT

A 67 year-old male seen for a longstanding corneal-conjunctival tumor.

TREATMENT

topical interferon α2b (IFN-α2b) 10 U/ml. A significant increase in lesion size was observed after 8 weeks. A surgical excision with cryotherapy was then performed. Pathological examination confirmed the diagnosis of squamous cell carcinoma. At this time the patient was found to have a positive HIV serology.

DISCUSSION

Conjunctival intraepithelial neoplasia (CIN) is a pre-cancerous lesion of the ocular surface. Medical treatment of CIN is essentially with IFN-α2b due to its antiviral/antitumor properties. In patients with HIV, treatment response could be paradoxical. We recommend serology for HIV before treatment with topical IFN-α2b.

Ocular surface squamous neoplasia - Review of etio-pathogenesis and an update on clinico-pathological diagnosis

Ocular surface squamous neoplasia (OSSN) has a varied clinical presentation, the diagnosis of which rests on the histopathological examination of the excised lesion. The term OSSN includes mild dysplasia on one end of the spectrum and invasive squamous cell carcinoma on the other end. This lesion has a multi factorial aetiology with interplay of several factors like exposure to ultraviolet radiation, various chemical carcinogens and viral infections, however role of individual agents is not well understood. With the upsurge of infection with human immunodeficiency virus, a changing trend is seen in the clinical presentation and prognosis of patients of OSSN even in developed countries. Anterior segment optical coherence tomography (OCT) and confocal microscopy, hold promise in in-vivo differentiation of intraepithelial neoplasia from invasive squamous cell carcinoma. Variants of squamous cell carcinoma like Mucoepidermoid carcinoma, spindle cell carcinoma and OSSN associated with HIV infection should be suspected in a case of aggressive clinical presentation of OSSN or with massive and recurrent tumours. Surgery, chemotherapy and immunotherapy are the various treatment modalities which in combination show promising results in aggressive, recurrent and larger tumours.

HIV and HPV infections and ocular surface squamous neoplasia: systematic review and meta-analysis

BACKGROUND

The frequency of ocular surface squamous neoplasias (OSSNs) has been increasing in populations with a high prevalence of infection with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and infection with human papillomavirus (HPV). We aimed to quantify the association between HIV/AIDS and HPV infection and OSSN, through systematic review and meta-analysis.

METHODS

The articles providing data on the association between HIV/AIDS and/or HPV infection and OSSN were identified in MEDLINE, SCOPUS and EMBASE searched up to May 2013, and through backward citation tracking. The DerSimonian and Laird method was used to compute summary relative risk (RR) estimates and 95% confidence intervals (95% CI). Heterogeneity was quantified with the I(2) statistic.

RESULTS

HIV/AIDS was strongly associated with an increased risk of OSSN (summary RR=8.06, 95% CI: 5.29-12.30, I(2)=56.0%, 12 studies). The summary RR estimate for the infection with mucosal HPV subtypes was 3.13 (95% CI: 1.72-5.71, I(2)=45.6%, 16 studies). Four studies addressed the association between both cutaneous and mucosal HPV subtypes and OSSN; the summary RR estimates were 3.52 (95% CI: 1.23-10.08, I(2)=21.8%) and 1.08 (95% CI: 0.57-2.05, I(2)=0.0%), respectively.

CONCLUSION

Human immunodeficiency virus infection increases the risk of OSSN by nearly eight-fold. Regarding HPV infection, only the cutaneous subtypes seem to be a risk factor.

[Non-AIDS defining malignancies, or the sleeping giant: an update]

Non-AIDS defining malignancies (NADM) are a very heterogeneous group of cancers with increasing importance in subjects with HIV infection. They develop in patients that are younger than general population and their clinical manifestations are usually atypical, with higher tumour grades, more aggressive clinical behaviour and metastatic disease. The outcome is poor, with rapid progression, a high rate of relapse, and a poor response to treatment. There are several factors that influence their development: HIV infection, chronic immunosuppression, and co-infection with some oncogenic viruses. The most frequent NADM are those associated with human papillomavirus infection, lung cancer, hepatic cancer, and Hodgkin lymphoma. Their management is based on three essential points: the treatment of the specific malignancy, the use of antiretroviral therapy, and the prophylaxis and treatment of opportunistic infections. The two factors significantly associated with prevention of NADM are a CD4+ lymphocyte count more than 500/mm(3), and an undetectable viral load.

The evaluation of human papillomavirus and p53 gene mutation in benign and malignant conjunctiva and eyelid lesions

Papillomas and squamous cell carcinomas are the most common conjunctival and eyelid lesions. The etiology is still unclear and recently human papillomavirus infection and p53 gene mutation have been taken into consideration. The aim of our study was the evaluation of HPV DNApresence and p53 gene mutation in 45 benign and 38 malignant squamous lesions of the conjunctiva and eyelid. For HPV detection PCR-RFLP and immunohistochemical reaction were used; for p53 gene mutation PCR-SSCP was used. Only 8.8% papillomas, 9.1% squamous cell cancers and 3.7% basal cell cancers (using PCR-RFLP method) and 26.6% papillomas, 7.4% squamous cell cancers and 9.1% basal cell cancers (using immunohisto-chemical reaction) were HPV positive. p53 gene mutation was evaluated in 24.4% papillomas, 54.5% squamous cell cancers and 22.2% basal cell cancers; most commonly in 6 and 7 exon. Human papillomavirus infection, opposite to p53 gene mutation, is not a significant etiological factor of the benign and malignant conjunctival and eyelid lesions development.

Changing cancer incidence in Kampala, Uganda, 1991-2006

Incidence rates of different cancers have been calculated for the population of Kyadondo County (Kampala, Uganda) for a 16-year period (1991-2006). This period coincides with continuing social and lifestyle changes and the peak and subsequent wane of the epidemic of HIV-AIDS. There has been an overall increase in the risk of cancer during the period in both sexes, with the incidence rates of cancers of the breast and prostate showing particularly marked increases (4.5% annually). Prostate cancer is now the most common cancer in men. The incidence of cancer of the esophagus, formerly the most common cancer in men and second in frequency in women, has remained relatively constant, whereas the incidence of cancer of the cervix, the most common malignancy in women, continues to increase. Since the early 1990s the incidence of Kaposi sarcoma (KS) in men has declined, and while remaining relatively constant in women, it has been diagnosed at progressively later ages. The rates of pediatric KS have declined by about 1/3rd. The incidence of squamous cell cancers of the conjunctiva has also declined since the mid 1990s. Cancer control in Uganda, as elsewhere in sub-Saharan Africa, involves meeting the challenge of emerging cancers associated with westernization of lifestyles (large bowel, breast and prostate); although the incidence of cancers associated with poverty and infection (liver, cervix, esophagus) shows little decline, the residual burden of the AIDS-associated cancers remains a major burden.

The biological properties of E6 and E7 oncoproteins from human papillomaviruses

More than 100 different human papillomavirus (HPV) types have been isolated so far, and they can be sub-grouped in cutaneous or mucosal according to their ability to infect the skin or the mucosa of the genital or upper-respiratory tracts. A sub-group of human mucosal HPVs, referred to as high-risk HPV types, is responsible for approximately 5% of all human cancers, which represents one-third of all the tumours induced by viruses. Epidemiological and biological studies have shown that HPV16 is the most oncogenic type within the high-risk group. Emerging lines of evidence suggest that, in addition to the high-risk mucosal HPV types, certain cutaneous HPVs are involved in skin cancer. HPV-associated cancers are intimately linked to HPV persistence and the accumulation of chromosomal rearrangements. The products of the early genes, E6 and E7, of the high-risk mucosal HPV types play a key role in both events. Indeed, these proteins have developed a number of strategies to evade host immuno-surveillance allowing viral persistence, and to alter cell cycle and apoptosis control, facilitating the accumulation of DNA damage/mutations. Often, the two oncoproteins target the same cellular pathways with different mechanisms, showing a strong synergism in promoting cellular transformation and neutralizing the immune response. Here, we review most of the findings on the biological properties and molecular mechanisms of the oncoproteins E6 and E7 from mucosal and cutaneous HPV types.

Intraepithelial and invasive squamous neoplasms of the conjunctiva in Ibadan, Nigeria: a clinicopathological study of 46 cases

BACKGROUND/AIMS

To retrospectively evaluate the clinicopathological features, treatment modalities and factors affecting prognosis in patients with both conjunctival intraepithelial and invasive squamous neoplasms.

METHOD

Review and analysis of clinical and pathological records of all cases histologically diagnosed in the Department of Pathology, University College Hospital, Ibadan, Nigeria between January 1990 and December 2004.

RESULTS

There were a total of 46 cases in 45 patients (eight intraepithelial carcinomas, 37 invasive squamous cell carcinomas (SCC) and a single case of mucoepidermoid carcinoma in a 71-year-old man). The intraepithelial neoplasms occurred in patients aged between 20 and 90 years. Seven of these patients had actinic changes on histology. For invasive SCC, patients' ages ranged from 18 to 84 years with a mean age of 53 years. Male to female ratio was 1:1. The majority presented with an orbital mass and loss of vision. Twenty-two (60%) of the patients with invasive SCC had enucleation or exenteration as the primary modality of treatment with or without radiotherapy or chemotherapy. Altogether for intraepithelial and invasive squamous neoplasms, the duration of presenting complaints ranged from 1 month to 5 years with an average of 2 years. Human immunodeficiency virus (HIV) infection and smoking were not significantly associated with these cases but a significant number had outdoor occupation. Low socioeconomic status and inability to afford treatment was common among our patients.

CONCLUSION

Patients with invasive SCC in Nigeria present late and have significant delay before having any form of treatment. This contributes to the poor outcome. Human papilloma virus (HPV) and actinic aetiology are possible strong causative agents in Nigerians.

Genital and cutaneous human papillomavirus (HPV) types in relation to conjunctival squamous cell neoplasia: a case-control study in Uganda

BACKGROUND

We investigated the role of infection with genital and cutaneous human papillomavirus types (HPV) in the aetiology of ocular surface squamous neoplasia (which includes both conjunctival intraepithelial neoplasia (CIN) and carcinoma) using data and biological material collected as part of a case-control study in Uganda.

RESULTS

Among 81 cases, the prevalence of genital and cutaneous HPV types in tumour tissue did not differ significantly by histological grade of the lesion. The prevalence of genital HPV types did not differ significantly between cases and controls (both 38%; Odds ratio [OR] 1.0, 95% confidence interval [CI] 0.4-2.7, p = 1.0). The prevalence of cutaneous HPV types was 22% (18/81) among cases and 3% (1/29) among controls (OR 8.0, 95% CI 1.0-169, p = 0.04).

CONCLUSION

We find no evidence of an association between genital HPV types and ocular surface squamous neoplasia. The prevalence of cutaneous HPV was significantly higher among cases as compared to controls. Although consistent with results from two other case-control studies, the relatively low prevalence of cutaneous HPV types among cases (which does not differ by histological grade of tumour) indicates that there remains considerable uncertainty about a role for cutaneous HPV in the aetiology of this tumour.

Increased Incidence of Squamous Cell Carcinoma of Eye After Kidney Transplantation

Squamous cell carcinoma (SCC) of the eye occurs at substantially increased rates in individuals with human immunodeficiency virus (HIV) infection, but it has not been reported in individuals with iatrogenic or congenital immune deficiency. In a national, population-based cohort of 10,180 renal transplantation patients from Australia with 86,898 person-years of follow-up, we ascertained primary incident cancers diagnosed in 1982-2003 by record linkage between the Australia and New Zealand Dialysis and Transplant Registry and the Australian National Cancer Statistics Clearing House. Standardized incidence ratios (SIRs) of cancer were calculated using age-, sex-, calendar year-, and state/territory-specific population cancer incidence rates. Statistical tests were two-sided. Five patients were diagnosed with ocular SCC after kidney transplantation (0.26 were expected), and the incidence was increased 20-fold (SIR = 19.5, 95% confidence interval [CI] = 6.3 to 45.5). Compared with the entire cohort, the five patients with ocular SCC after transplantation were more likely to have resided in the subtropical state of Queensland (60% versus 17%, P = .04), to have had end-stage kidney disease as a result of glomerulonephritis (100% versus 46%, P = .02), and to have a history of cutaneous SCC (100% versus 29%, P = .002). The increased incidence of ocular SCC after kidney transplantation and after HIV infection strongly suggests that this neoplasm is an immune deficiency-associated cancer. Our data also support an interaction between immune suppression and sun exposure in the development of ocular SCC after kidney transplantation.

Anterior Segment and External Ocular Disorders Associated with Human Immunodeficiency Virus Disease

The eye is a common site for complications of human immunodeficiency virus (HIV) infection. Although cytomegalovirus retinitis remains the most prevalent of the blinding ocular disorders that can occur in individuals with the acquired immunodeficiency syndrome (AIDS), several important HIV-associated disorders may involve the anterior segment, ocular surface, and adnexae. Some of these entities, such as Kaposi sarcoma, were well described, but uncommon, before the HIV epidemic. Others, like microsporidial keratoconjunctivitis, have presentations that differ between affected individuals with HIV disease and those from the general population who are immunocompetent. The treatment of many of these diseases is challenging because of host immunodeficiency. Survival after the diagnosis of AIDS has increased among individuals with HIV disease because of more effective antiretroviral therapies and improved prophylaxis against, and treatment of, opportunistic infections. This longer survival may lead to an increased prevalence of anterior segment and external ocular disorders. In addition, the evaluation and management of disorders such as blepharitis and dry eye, which were previously overshadowed by more severe, blinding disorders, may demand increased attention, as the general health of this population improves. Not all individuals infected with HIV receive potent antiretroviral therapy, however, because of socioeconomic or other factors, and others will be intolerant of these drugs or experience drug failure. Ophthalmologists must, therefore, still be aware of the ocular findings that develop in the setting of severe immunosuppression. This article reviews the spectrum of HIV-associated anterior segment and external ocular disorders, with recommendations for their evaluation and management.

Surgical Excision, Cryotherapy, Autolimbal Transplantation and Mitomycin-C in Treatment of Conjunctival–corneal Intraepithelial Neoplasia

PURPOSE

To report surgical excision, cryotherapy, autologous conjunctival-limbal transplantation and topical mitomycin C (MMC) in the patient with extensive conjunctival-corneal intraepithelial neoplasia.

METHODS

Case report and literature review.

RESULTS

A 75-year-old woman was referred to our department with the diagnosis of conjunctival-corneal neoplasia. Slit-lamp microscopic examination revealed an extensive papilliform tumoral mass invading the limbus at 360-degrees, and bulbar conjunctiva and cornea. Visual acuity was finger counting from 2 m in the right eye and 20/20 in the left eye. We performed total surgical excision, cryotherapy and autologous conjunctival-limbal transplantation in the right eye. Mitomycin-C 0.02% eye drops four times a day were prescribed for 4 weeks after the surgery. After the treatment, the visual acuity increased to 0.7 in the right eye. Corneal epithelium completely healed within 1 week after the surgery. No corneal epithelium-related problem or neoplasia recurrence were noted during the 2-year follow-up period.

CONCLUSIONS

This technique may be useful in reconstruction of eyes with extensive neoplastic involvement of the conjunctiva, limbus, and cornea. In addition, mitomycin C drops may be useful in preventing postoperative recurrence of conjunctival-corneal intraepithelial neoplasia.

Conjunctival squamous cell carcinoma in a patient with hemodialysis-related porphyria cutanea tarda

Hemodialysis-related porphyria cutanea tarda (HRPCT) is characterized by porphyria-like blisters on sun-exposed parts of the face, arms and hands due to elevated porphyrin levels. Conjunctival squamous cell carcinoma (CSCC) is a rare cancer that typically occurs on the sun-damaged ocular surface of elderly male patients. Herein, we report a case of CSCC in a 72-year-old patient who had been on hemodialysis for 8 years, and had been followed up with a diagnosis of HRPCT for 3 years. To our knowledge, this is the first case report documenting an association between HRPCT and CSCC, which may reflect a pathogenetic process connecting them.

Adverse effects of ultraviolet radiation: a brief review

Solar ultraviolet radiation (UVR) has always been part of the environment of man. UVB is required for the conversion of 7-deoxycholesterol to vitamin D, which is critically important in the maintenance of healthy bones and research is making clear that it has other potential roles in maintenance of human health. Exposure to UVR, whether of solar or artificial origin, also carries potential risks to human health. UVR is a known carcinogen and excessive exposure-at least to solar radiation in sunlight-increases risk of cancer of the lip, basal cell, and squamous cell carcinoma of the skin and cutaneous melanoma, particularly in fair skin populations. There is also evidence that solar UVR increases risk of several diseases of the eye, including cortical cataract, some conjunctival neoplasms, and perhaps ocular melanoma. Solar UVR may also be involved in autoimmune and viral diseases although more research is needed in these areas. Artificial UVR from tanning beds, welding torches, and other sources, may contribute to the burden of disease from UVR. This brief review will assess the human evidence for adverse health effects from solar and artificial UVR and will attempt to assign a degree of certainty to the major disease-exposure relationships based on the weight of available scientific evidence.

The aetiology and associations of conjunctival intraepithelial neoplasia

AIM

To summarise the main causes and associations of conjunctival intraepithelial neoplasia (CIN) found in the literature to date.

METHOD

Literature search using Ovid databases on the NHS Scotland E-library, Medline, and the Cochrane Library. The internet search engine Google Scholar was also used to identify relevant articles.

RESULTS

The main causes and associations of CIN in the literature are sun exposure and distance from the equator; human papillomavirus infection, increased p53 expression, and HIV seropositivity. It has been found that in HIV positive individuals CIN is on the increase with people being affected with more aggressive tumours at younger ages.

CONCLUSION

Given that CIN is becoming more common in HIV infected populations and that it has the potential to cause severe disability, it is important to improve our understanding of the condition. Early identification of CIN by an understanding of its aetiology and associations may enable the implementation of preventative measures to reduce its incidence and potentially lead to the diagnosis and further management of conditions such as HIV. Young people presenting with CIN in particular may benefit from HIV testing.

Adjunctive Treatment With Interferon ??-2b May Decrease the Risk of Papilloma-Associated Conjunctival Intraepithelial Neoplasm Recurrence

PURPOSE

To report a case of bilateral papilloma virus-positive conjunctival intraepithelial neoplasm and the treatment results of using adjunctive interferon alpha-2b.

METHODS

Case report and literature review.

RESULTS

A 73-year-old man underwent subtotal excisional biopsy of the 270-degree gelatinous limbal lesion of the right eye to avoid creating a limbal deficiency and cicatricial change. Total excisional biopsy of the temporal elevated leukoplakic limbal lesion was performed on his left eye. Histology examination showed bilateral intraepithelial neoplasia, and human papilloma virus-16 and -18 were detected by polymerase chain reaction in both lesions. Two supplemental perilesional injections of interferon alpha-2b in the right eye were given, and the residual mass decreased in size gradually and completed clinical resolution 7 weeks following initial surgery. Although no recurrence was noticed in the right eye, recurrence of the conjunctival intraepithelial neoplasm lesion was noticed in the left eye.

CONCLUSION

Adjunctive therapy might lower CIN recurrence rate, especially in extensive lesions, when surgical excision cannot ensure a tumor-free margin. Our bilateral case provided a good control example for the recurrence with or without adjunctive therapy.

Infections and immune factors in cancer: the role of epidemiology

An infective, mostly viral, basis has been found in an increasing number of different human cancers. In all cases, the neoplasm is a rare response to the relevant infection, which is usually present in persistent form, and requiring specific cofactors for malignancy to develop. In some cases, epidemiological evidence of infectivity preceded and promoted identification of the specific infection involved and even the discovery of the microbe itself, as in Burkitt's lymphoma and cervix cancer. In other cases, the discovery of the agent came first as in stomach and nasopharynx cancers, and epidemiology has been concerned mainly with confirming the relationship, measuring the size of the risk and identifying cofactors. Infection-linked cancers include some of the commonest malignancies in certain large world regions, amounting to over 20% of all cancer in the developing countries. In addition to these cancers are others such as childhood leukaemia that show features indicative of an infective basis though no underlying agent has been identified. Advances in this field invite speculation about possible future discoveries and how these might be promoted. However, in that majority of cancers that are unrelated to sexual behaviour, there will be nothing even at the population level to suggest an infective basis because what is transmitted from one individual to another is not the neoplasm itself, but the underlying, often silent, infection to which the malignancy is an uncommon response. The increasing prevalence of immune impairment in human populations, as a result of the use of immunosuppressive drugs with organ transplants and the spread of HIV infection, has produced marked effects on cancer incidence in the affected groups including increases, of skin cancers, non-Hodgkin's lymphoma and Kaposi's sarcoma and to a lesser extent of many other cancers, in some cases at least due to the release from immunological control of incipient infection-based malignancies.

Epidermodysplasia verruciformis human papillomavirus types and carcinoma of the conjunctiva: a pilot study

A total of 21 squamous-cell carcinoma of the conjunctiva (SCC) and 22 control subjects had conjunctival samples tested for human papillomavirus (HPV) types using PCR-based assays. Epidermodysplasia verruciformis HPV types were found in 86% of SCC cases and 36% of control subjects (Odds ratio=12.0), suggesting a role of HPVs in the aetiology of SCC.

Ocular Surface Squamous Neoplasia

Even though ocular surface squamous neoplasia (OSSN) has been recognized for well over a century, the past decade has witnessed advances that have helped rewrite many of the paradigms for the diagnosis and management of these lesions. OSSN occurs predominantly in the elderly for whom they are the third most common oculoorbital tumors after melanoma and lymphoma. In addition to advanced age and male sex, other major risk factors linked to its pathogenesis are ultraviolet light, cigarette smoking, and the human papilloma virus. Although the latter has been linked to OSSN for nearly 4 decades, its identification and role in the pathogenesis of these tumors has been elucidated recently and is addressed in detail in this review. Newer techniques of impression cytology represent a noninvasive and reliable method of diagnosing OSSN and monitoring treated cases. The efficacy of chemotherapeutic agents such as mitomycin C and 5-fluorouracil have been proven in the recent past, making them a clear alternative to the time-tested treatment of surgical excision and cryotherapy. Early reports on the efficacy of topical Iterferon alpha 2b indicate significant promise in providing another alternative for the treatment of some of these neoplasms. These advances thus represent a minimally invasive and highly successful approach to the diagnosis and treatment of OSSN.

Squamous cell carcinoma of the conjunctiva in patients with atopic eczema

PURPOSE

To report squamous cell carcinoma (SCC) of the conjunctiva in patients with atopic eczema.

METHODS

A retrospective study of six patients with conjunctival SCC associated with atopic eczema. Clinical and pathologic records were reviewed.

RESULTS

Ten patients with conjunctival SCC were seen from October 1999 to May 2002 at the Department of Ophthalmology at the University of Essen. Six of 10 patients had also atopic eczema. These six patients were treated either with local excision and ocular surface reconstruction or proton beam radiotherapy. None of the patients had local recurrences or metastases.

CONCLUSION

Atopic eczema is a common dermatological disease. An association with conjunctival SCC has not been reported so far. Squamous cell carcinoma has also been found in patients with AIDS and other immunosuppressed individuals. The dysfunction of T lymphocytes found in these disorders might play a crucial role in the malignant transformation of conjunctival tissue. Because of the reported frequency of SCC, patients with atopic eczema should be monitored for abnormalities.

The epidemiology of conjunctival squamous cell carcinoma in Uganda

As part of a larger investigation of cancer in Uganda, we conducted a case-control study of conjunctival squamous cell carcinoma in adults presenting at hospitals in Kampala. Participants were interviewed about social and lifestyle factors and had blood tested for antibodies to HIV, KSHV and HPV-16, -18 and -45. The odds of each factor among 60 people with conjunctival cancer was compared to that among 1214 controls with other cancer sites or types, using odds ratios, estimated with unconditional logistic regression. Conjunctival cancer was associated with HIV infection (OR 10.1, 95% confidence intervals [CI] 5.2-19.4; P<0.001), and was less common in those with a higher personal income (OR=0.4, 95% CI 0.3-0.7; P<0.001)[corrected]. The risk of conjunctival cancer increased with increasing time spent in cultivation and therefore in direct sunlight (chi2 trend=3.9, P=0.05), but decreased with decreasing age at leaving home (chi2 trend=3.9, P=0.05), perhaps reflecting less exposure to sunlight consequent to working in towns, although both results were of borderline statistical significance. To reduce confounding, sexual and reproductive variables were examined among HIV seropositive individuals only. Cases were more likely than controls to report that they had given or received gifts for sex (OR 3.5, 95% CI 1.2-10.4; P=0.03), but this may have been a chance finding as no other sexual or reproductive variable was associated with conjunctival cancer, including the number of self-reported lifetime sexual partners (P=0.4). The seroprevalence of antibodies against HPV-18 and -45 was too low to make reliable conclusions. The presence of anti-HPV-16 antibodies was not significantly associated with squamous cell carcinoma of the conjunctiva (OR 1.5, 95% CI 0.5-4.3; P=0.5) and nor were anti-KSHV antibodies (OR 0.9, 95% CI 0.4-2.1; P=0.8). The 10-fold increased risk of conjunctival cancer in HIV infected individuals is similar to results from other studies. The role of other oncogenic viral infections is unclear.

The causal relation between human papillomavirus and cervical cancer

The causal role of human papillomavirus infections in cervical cancer has been documented beyond reasonable doubt. The association is present in virtually all cervical cancer cases worldwide. It is the right time for medical societies and public health regulators to consider this evidence and to define its preventive and clinical implications. A comprehensive review of key studies and results is presented.

p53 protein expression in conjunctival squamous cell carcinomas of domestic animals

The expression of p53 protein was investigated in eight formalin-fixed, paraffin-embedded conjunctival squamous cell carcinomas of five horses and one cow, dog and cat each by an immunohistochemical procedure in order to evaluate protein overexpression. Anti-human p53 protein mouse monoclonal antibodies known to be cross-reactive with p53 protein of the animal species examined were used. Positive p53 nuclear immunostaining was detected in five equine, one bovine and one feline cases. Conversely, no p53 immunostaining was found in the only canine case examined. These results demonstrate a frequent p53 overexpression in conjunctival squamous cell carcinoma that could be related to UV-induced mutations of the p53 tumor suppressor gene.

A case-control study of human immunodeficiency virus infection and cancer in adults and children residing in Kampala, Uganda

Uganda offers a unique setting in which to study the effect of human immunodeficiency virus-1 (HIV-1) on cancer. HIV-1 is prevalent there, and cancers which are known to be HIV-associated, such as Kaposi's sarcoma and Burkitt's lymphoma, are endemic. Adults residing in Kampala, Uganda, presenting with cancer in city hospitals were interviewed and had an HIV test. Of the 302 adults recruited, 190 had cancers with a potentially infectious aetiology (cases). The remaining 112 adults with tumours not known to have an infectious aetiology formed the control group. In addition, 318 children who were also Kampala residents were recruited and tested for HIV: 128 with cancer (cases) and 190 with non-malignant conditions (controls). HIV seroprevalence was 24% in adult controls and 6% in childhood controls. The odds of HIV seropositivity among cases with specific cancers (other than Kaposi's sarcoma in adults) were compared with that among controls, using odds ratios (ORs), estimated with unconditional logistic regression. All ORs were adjusted for age (<5, 5-14, 15-19, 30-44, 45+) and sex and, in adults, also for the number of lifetime sexual partners (1 or 2, 3-9, 10+). In adults, HIV infection was associated with a significantly (p < 0.05) increased risk of non-Hodgkin's lymphoma [OR = 6.2, 95% confidence interval (CI) 1.9-19.9, based on 21 cases] and conjunctival squamous-cell carcinoma (OR = 10.9, 95% CI 3.1-37.7, based on 22 cases) but not with cancer at other common sites, including liver and uterine cervix. In children, HIV infection was associated with a significantly increased risk of Kaposi's sarcoma (OR = 94.9, 95% CI 28.5-315.3, based on 36 cases) and Burkitt's lymphoma (OR = 7.5, 95% CI 2.8-20.1, based on 33 cases) but not with other cancers. The pattern of HIV-associated cancers in Uganda is broadly similar to that described elsewhere, but the relative frequency of specific cancers, such as conjunctival carcinoma, in HIV-infected people differs.

Cancer incidence in Blantyre, Malawi 1994-1998

In this paper, we report the first results from the population-based cancer registry for Blantyre district, Malawi, for the period 1994-1998. In this 5-year period, 1245 cases were recorded in males (an estimated age-standardized incidence of 92.0 per 100,000) and 1003 in females (an age standardised rate (ASR) of 88.8 per 105). The overall percentage of cases with histological verification was just 41.8%, indicating that case-finding outside the laboratory had been quite successful; nevertheless the rather low rates suggest possible underdiagnosis of cancer, as well as cases missed. As in other reports from the region, the contemporary pattern is dominated by Kaposi's sarcoma (KS) (55.2% cancers in men, 28% in women), the effect of the evolving epidemic of AIDS. The incidence of cervix cancer in women is high (ASR 26.2 per 105), and there are moderately high rates of oesophageal cancer (ASR 15.4 per 105 in men, 9.3 per 105 in women). In childhood, the cancer profile is dominated by Burkitt's lymphoma, which accounts for 42.4% of cancers; KS is now the second most frequent cancer of childhood.

Trends in cancer incidence in Kyadondo County, Uganda, 1960-1997

Incidence rates of different cancers have been calculated for the population of Kyadondo County (Kampala, Uganda) for four time periods (1960-1966; 1967-1971; 1991-1994; 1995-1997), spanning 38 years in total. The period coincides with marked social and lifestyle changes and with the emergence of the AIDS epidemic. Most cancers have increased in incidence over time, the only exceptions being cancers of the bladder and penis. Apart from these, the most common cancers in the early years were cervix, oesophagus and liver; all three have remained common, with the first two showing quite marked increases in incidence, as have cancers of the breast and prostate. These changes have been overshadowed by the dramatic effects of the AIDS epidemic, with Kaposi's sarcoma emerging as the most common cancer in both sexes in the 1990s, and a large increase in incidence of squamous cell cancers of the conjunctiva. In the most recent period, there also seems to have been an increase in the incidence of non-Hodgkin lymphomas. So far, lung cancer remains rare. Cancer control in Uganda, as elsewhere in sub-Saharan Africa, faces a threefold challenge. With little improvement in the incidence of cancers associated with infection and poverty (liver, cervix, oesophagus), it must face the burden of AIDS-associated cancers, while coping with the emergence of cancers associated with Westernization of lifestyles (large bowel, breast and prostate).

Aids and cancer in Africa: the evolving epidemic in Zimbabwe

BACKGROUND

Zimbabwe is severely affected by the AIDS epidemic, and many cancers in African populations are related to infectious agents.

OBJECTIVE

To study the current pattern, and short-term changes in incidence, of cancers related to infectious agents (and especially to HIV), with respect to the evolving epidemic of AIDS.

METHODS

Analysis of data on the African population of Harare, Zimbabwe, from the Zimbabwe Cancer Registry, for the period 1990-1995. Comparison with data on prevalence of HIV seropositivity, and notifications of AIDS.

RESULTS

Comparing results from 1993-1995 with those for 1990-1992 shows a continuing increase in the incidence of Kaposi's sarcoma with a doubling of the rates in both men and women. A dramatic increase in the incidence of squamous cell tumours of the conjunctiva was also observed, as well as a significant increase in the incidence of non-Hodgkin's lymphoma in women. There was no apparent increase in risk for Hodgkin's disease, myeloma, liver cancer, or cancer of the cervix.

CONCLUSIONS

The AIDS epidemic has had a dramatic effect on the profile of cancer. The changes in incidence involve several cancers previously linked to AIDS in North America and Europe.

AIDS-related cancers in Africa: maturation of the epidemic in Uganda

BACKGROUND

The AIDS epidemic has passed its peak in Uganda, with possible consequences for the risk of cancers related to infectious agents.

OBJECTIVE

To compare the incidence of cancers possibly linked to infections with HIV, before the AIDS epidemic (the 1960s), at its high point (the early 1990s) when HIV-seroprevalence and AIDS notifications peaked, and after the onset of its decline in the later 1990s.

METHODS

Analysis of incidence rates of infection-associated cancers in the population of Kyadondo county, in 1960-1971, 1991-1994, and 1995-1997. Comparison with data on prevalence of HIV infection, and notifications of AIDS.

RESULTS

The incidence of Kaposi's sarcoma has increased enormously since the 1960s, with a shift to earlier age at onset, and more generalized and nodal disease; there has been little change in the profile during the 1990s. There was a large increase in incidence of squamous cell carcinomas of the conjunctiva, which has continued through the 1990s. Non-Hodgkin's lymphomas showed little increase in incidence until the most recent period, in which the incidence has increased both in children (particularly Burkitt's lymphomas) and adults. Although the incidence of cervical cancer was higher in the 1990s than the 1960s, it seems doubtful that this is related to HIV infection. Certain other cancers which have been linked to AIDS in western populations (Hodgkin's disease, anal carcinoma, childhood leiomyosarcoma) show no changes in risk.

CONCLUSION

The AIDS epidemic has dramatically changed the profile of cancer in Uganda. Trends in the AIDS-related cancers are consistent with current knowledge concerning the mechanisms behind the increased risk. The incidence of certain cancers with a viral aetiology (liver, cervix, penis, Hodgkin's disease) appears not to have been influenced by AIDS.

Squamous cell carcinoma with necrotizing scleritis

PURPOSE

To report on a case of limbal squamous cell carcinoma (SCC) with necrotizing scleritis in a young, previously healthy, white Australian male.

METHODS

A 31-year-old man presented with a left limbal lesion intermittently causing a red eye and foreign body sensation. He had enjoyed surfing for many years. Repeat HIV tests were negative and the lesion was biopsied.

RESULTS

Biopsy showed a well-differentiated SCC apparently arising in an intra-epithelial (in situ) carcinoma of the conjunctiva. The lesion was excised and a corneoscleral graft repair was performed.

CONCLUSION

The present case highlights the potential for a significant increase in the prevalence of ocular surface neoplasia in healthy young people who have had excessive UV-B exposure.

Intraepithelial and invasive squamous cell carcinoma of the conjunctiva: analysis of 60 cases

AIM

To evaluate the clinical features, treatment results, and recurrence rates in patients with either intraepithelial or invasive squamous cell carcinoma of the conjunctiva.

METHODS

Retrospective analysis of 60 cases (22 conjunctival intraepithelial and 38 invasive squamous cell carcinomas) to determine patterns of clinical presentation, aetiological factors, and treatment results. The mean patient age was 64 years old. 70% of the patients were male. Patients were treated with a variety of therapies, depending on the degree of tumour involvement; most cases were treated with frozen section controlled excision and adjunctive cryotherapy. Modified eye wall resection or enucleation was done for intraocular invasion and exenteration was done for orbital involvement.

RESULTS

Red eye (68%) and ocular irritation (57%) were the most common presenting symptoms. 44% of the patients had other eye findings consistent with extensive solar exposure. 20% of the patients had a history of malignant skin tumours. Visceral malignancies developed in 8%. Scleral involvement was present in 14 (37%), intraocular involvement in five (13%), and orbital invasion in four (11%) cases with invasive squamous cell carcinoma. After a mean follow up of 56 months (18-226 months) the rate of new or recurrent tumours was 4.5% for intraepithelial squamous carcinoma and 5.3% for invasive squamous cell carcinoma. No patient developed metastases or tumour related deaths.

CONCLUSION

Excision with intraoperative control of the surgical margins and adjunctive cryotherapy results in good tumour control rates.

Overview of the epidemiology of immunodeficiency-associated cancers

Immunodeficiency, be it congenital, therapeutic, or infectious in origin, increases the risk of certain, but not all, types of cancer. A common feature of these cancers is that specific infectious agents appear to be important in their etiology, not only in immunodeficient subjects but also in the general population. People with acquired immunodeficiency syndrome (AIDS) are at an increased risk of Kaposi's sarcoma, non-Hodgkin's lymphoma, Hodgkin's disease, squamous cell carcinoma of the conjunctiva, and childhood leiomyosarcoma. It is striking that most of these cancers have been associated with specific human herpesvirus (HHV) infections: HHV-8 with Kaposi's sarcoma and the closely related Epstein-Barr virus with non-Hodgkin's lymphoma, Hodgkin's disease, and possibly also with childhood leiomyosarcoma. Moreover, similar associations between these viruses and cancer have been found, albeit inconsistently, in people who are not immunosuppressed. Further research is needed to establish whether the risk of other cancers is also increased in people with AIDS, although, if so, the cancers are likely to be rare or to have comparatively small associated relative risks. Existing evidence suggests that there may be no marked increase in the risk of two common cancers that are known to be caused by infectious agents--hepatocellular carcinoma and invasive carcinoma of the uterine cervix. The apparent lack of an increase in invasive cervical cancer is unexpected and needs further investigation, especially since the prevalence of cervical infection with human papillomaviruses and of low-grade preneoplastic changes in the cervical epithelium is increased in women with AIDS. With the prospect of improved survival in people with AIDS, the effect of immunosuppression on cancer is likely to become an increasingly important issue.