Germline brca2 sequence variants in patients with ocular melanoma

On the basis, chiefly, of anecdotal reports of cases of ocular melanoma (OM) occurring in families with inherited susceptibility to breast cancer due to brca2 germline mutations, we examined the frequency of brca2 alterations in a series of 62 ocular melanoma cases. These cases were preferentially selected on the basis of reported family history of breast or ovarian cancer, or OM, although the series also included a randomly selected set of cases without family history of cancer. A total of 7 germline alterations were found, of which 3 were likely to be associated with disease. While all 3 deleterious mutations were found in patients who also had a personal history of breast cancer, only 1 of the 3 families had a family history of breast/ovarian cancer or OM. Although germline brca2 mutations may account for a small proportion of all OM cases, there may be additional loci that contribute to familial aggregation of OM and to the familial association between OM and breast cancer.

Lactation in relation to postmenopausal breast cancer

A modest inverse association between lactation and breast cancer risk has most consistently been observed in premenopausal women, and certain breastfeeding patterns, such as prolonged duration and early age at first lactation, may be important determinants of risk. However, these associations have not generally been observed in relation to postmenopausal breast cancer. As part of a multicenter population-based case-control study, the authors examined postmenopausal breast cancer risk according to breastfeeding characteristics. Breast cancer patients aged 50-79 years were identified from statewide tumor registries in Massachusetts, New Hampshire, and Wisconsin from July 1992 through July 1995. Similarly aged control women were randomly selected from population lists. Information regarding lactation history and breast cancer risk factors was obtained through telephone interviews. This analysis included only data on parous postmenopausal women (3,633 cases and 3,790 controls). After adjustment for age, parity, age at first birth, and other breast cancer risk factors, breastfeeding for at least 2 weeks was associated with a slightly reduced risk of breast cancer in comparison with women who had never lactated (relative risk = 0.87, 95% confidence interval 0.78-0.96). There was only a modest suggestion that increasing cumulative duration of lactation was inversely associated with breast cancer risk; the relative risk for women who had breastfed for > or =24 months was 0.73 (95% confidence interval 0.56-0.94) (p-trend for duration = 0.10). Age at first lactation was not consistently associated with risk. Modest inverse associations appeared to persist even up to 50 years since first lactation. Use of hormones to suppress lactation was not associated with postmenopausal breast cancer, nor was inability to breastfeed related to risk. These results suggest that lactation may have a slight and perhaps long-lasting protective effect on postmenopausal breast cancer risk.

Childbearing history associated with improved survival in choroidal melanoma

BACKGROUND

Research in cutaneous melanoma suggests that women may experience better tumor-dependent survival than men, and some studies have shown that the advantage is specific to childbearing.

OBJECTIVE

To examine whether childbearing may be a favorable prognostic factor in melanoma of the uveal tract.

DESIGN

Prospective follow-up study.

SETTING

Hospital.

MAIN OUTCOME MEASURE

Death from metastatic choroidal melanoma.

METHODS

We evaluated a consecutive series of 1818 patients with choroidal melanoma, 748 parous and 165 nulliparous women and 905 men, after treatment with proton irradiation. Three hundred fifty-two deaths from metastasis were documented in follow-up.

RESULTS

Overall multivariate-adjusted death rates from metastasis were approximately 25% higher in nulliparous women (relative risk [RR], 1.23; 95% confidence interval [CI], 0.83-1.82) and men (RR, 1.25; 95% CI, 1.00-1.56) than in women who had given birth. The protective influence of parity was strongest in the early period following diagnosis and treatment (RR, 1.58; 95% CI, 0.88-2.86, and RR, 1.51; 95% CI, 1.04-2.19, in nulliparous women and men, respectively, during the first 36 months of follow-up). The level of protection increased with the number of live births (P for trend, .04).

CONCLUSION

These data provide support for the hypothesis that a history of childbearing confers protection from death in choroidal melanoma.

Iris color as a prognostic factor in ocular melanoma

BACKGROUND

Ocular melanoma may be more prevalent among patients with light irises than those with dark irises.

OBJECTIVE

To examine a large clinical series of patients with intraocular melanoma to determine if light irises are associated with increased risk of death from these tumors.

METHODS

A total of 1162 patients treated with proton irradiation between 1984 and 1996 were observed through 1997.

RESULTS

Iris color in the patients was blue or gray in 48%, green or hazel in 30%, and brown in 23%. Tumors in patients with blue or gray irises were less heavily pigmented (P<.001) and closer to the optic disc and macula (P<.001). Five- and 10-year metastasis-related death rates were 0.14 and 0.21, respectively, for those with blue or gray irises and 0.10 and 0.15, respectively, for those with darker irises (P = .02). In a Cox proportional hazards regression controlling for tumor characteristics, patients with blue or gray irises died of metastatic disease at a rate 1.90 times (95% confidence interval, 1.26-2.85) that of patients with brown irises. The rate of metastatic death was not significantly elevated for those with green or hazel irises (relative risk, 1.43; 95% confidence interval, 0.91-2.23).

CONCLUSION

Patients with blue or gray irises appear to be at increased risk of metastatic death from choroidal melanoma, independent of other risk factors.

The relation of breast size to breast cancer risk in postmenopausal women (United States)

OBJECTIVE

Breast size has been hypothesized to predict a woman's risk of breast cancer although studies in the main have not supported an association. In a large, population-based case-control study we examined whether breast size might emerge as a significant risk factor among very lean women in whom breast size might be a truer reflection of the volume of gland mass at risk for malignant change.

METHODS

The data derive from a population-based case-control study of women aged 50 to 79 years conducted in several New England states and Wisconsin. Incident cases of invasive breast cancer (n = 2015) were identified through state tumor registries and controls (n = 2556) were selected at random within age strata from population lists. Telephone interviews were conducted to obtain information on known and suspected risk factors which included bra dimensions (cup and back size) prior to a first birth, or at the age of 20 for nulliparous women.

RESULTS

We observed a significant positive association for cup size which was limited to women who were the most lean as young adults based on chest circumference. Among those reporting a chest size under 34 inches multivariate-adjusted relative risks were 1.34 (95% CI: 1.04 to 1.74) for cup size B, and 1.76 (95% CI: 1.04 to 3.01) for cup size C and larger, compared to a cup size smaller than B, and the trend for increasing cup size was statistically significant (P = 0.005). There was no relation with breast size among women reporting an average or larger back circumference (34 inches or larger).

CONCLUSION

Breast size before a pregnancy is a positive predictor of postmenopausal breast cancer, but this association is limited to those who were especially lean as young women.

Exposure to breast milk in infancy and adult breast cancer risk

BACKGROUND

There is considerable interest in the possibility of an infectious etiology for human breast cancer. Although studies have shown that certain strains of mice transmit mammary tumor virus via breast milk, few epidemiologic studies have addressed this topic in humans.

METHODS

We evaluated the relationship between having been breast-fed as an infant and breast cancer risk among 8299 women who participated in a population-based, case-control study of breast cancer in women aged 50 years or more. Case women were identified through cancer registries in three states (Massachusetts, New Hampshire, and Wisconsin); control women were identified through statewide driver's license lists (age <65 years) or Medicare lists (ages 65-79 years). Information on epidemiologic risk factors was obtained through telephone interview. We used multiple logistic regression to assess having been breast-fed and maternal history of breast cancer in relation to breast cancer occurrence both in premenopausal women (205 case women; 220 control women) and in postmenopausal women (3803 case women; 4071 control women).

RESULTS

We found no evidence that having been breast-fed increased breast cancer risk in either premenopausal women (odds ratio [OR] = 0.65; 95% confidence interval [CI] = 0.41-1.04) or postmenopausal women (OR = 0.95; 95% CI = 0.85-1.07). In addition, breast cancer risk was not increased by having been breast-fed by a mother who later developed breast cancer.

CONCLUSION

Our results do not support the hypothesis that a transmissible agent in breast milk increases breast cancer risk. Because premenopausal women were not well represented in our study population, our findings with regard to this group may not be generalizable and should be viewed with caution.

Risk factors for breast cancer in women with a breast cancer family history

Family history (FH) is an important indicator of a woman's future risk of developing breast cancer. Using data collected in a large population-based case-control study (6705 cases and 9341 controls), we examined the associations of breast cancer with known risk factors in women reporting a first-degree FH (mother or sister), with an emphasis on lifestyle determinants that may be altered to reduce risk. First-degree FH was reported by 18.4% (n = 1234) of cases and 11.3% (n = 1058) of controls; the overall relative risk (RR) for breast cancer associated with a positive history was 1.70 [95% confidence interval (CI), 1.55-1.87] and 2.34 (95% CI, 1.80-3.02) for breast cancer at age 45 years or younger. Among women with a FH, statistically significant inverse associations were observed for increasing parity (RR per birth = 0.90; P < 0.0001), intake of carotene-rich foods (RR for >2000 IU/day = 0.73; P = 0.02), and strenuous activity as a young adult (RR per episode/week = 0.93; P = 0.02). Recent alcohol consumption increased risk (RR per 13 g/week = 1.21; P = 0.02), as did weight gain during adult life in postmenopausal women (RR per 5 kg = 1.08; P = 0.001). Breast-feeding for any duration was associated with a lower RR in parous, premenopausal women (RR = 0.59; P = 0.04). Associations for most risk factors with breast cancer were similar among women with and without a FH of breast cancer; however, a stronger inverse association was observed for parity in women with a positive history (P for interaction = 0.04). Based on these data, women with a FH may reduce their excess risk of breast cancer through adjustments in lifestyle and reproductive choices. The risk associated with FH of breast cancer seems to be largely independent of other known risk factors.

Survival implications of enucleation after definitive radiotherapy for choroidal melanoma: an example of regression on time-dependent covariates

OBJECTIVE

To evaluate whether the removal of the eye after radiotherapy alters the rates of metastatic death in patients with melanoma of the choroid.

PATIENTS AND METHODS

Using an extension of the Cox model, we based our analysis on a cohort of 1541 consecutive patients with unilateral choroidal or ciliary body melanoma treated with protons (70 cobalt-gray equivalent in 5 to 7 fractions) at the Harvard University (Boston, Mass) cyclotron between July 1, 1975, through December 31, 1993, and who were observed prospectively up to September 30, 1995. Patient survival and the status of the treated eye were updated annually.

RESULTS

By September 1995 (median follow-up among survivors, 8 years), 137 patients underwent enucleation after radiotherapy for complications (n=103) or tumor regrowth (n=34). The overall 10-year rate of eye retention was 89% (95% confidence interval, 87%-91%). Of the 1541 patients, 300 died of tumor metastasis, 38 following enucleation of the affected eye (mean interval from enucleation to death, 25 months). The multivariate rate ratio for metastatic death associated with enucleation (modeled as a time-dependent covariate) was 0.9 (95% confidence interval, 0.6-1.4) for enucleation due to complications and 3.8 (95% confidence interval, 2.3-6.3) for enucleation associated with tumor regrowth.

CONCLUSIONS

In the absence of tumor viability, enucleation after primary irradiation for choroidal melanoma has no deleterious effect on patients' survival. Enucleation concurrent with tumor regrowth is associated with high death rates; growth of the tumor in the eye may presage systemic recurrence and death from metastasis.

An evaluation of tumour vascularity as a prognostic indicator in uveal melanoma

Experimental and clinical evidence suggests that tumour angiogenesis plays a role in the tendency for certain neoplasms, including cutaneous melanomas, to metastasize. We evaluated whether tumour vasculature is associated with the rate of metastases in patients with melanoma of the choroid or ciliary body. The study was based on a group of 63 patients enucleated between 1976 and 1984 with paraffin-embedded tissue blocks available for sectioning and with known survival status as of December 1988. Vessel endothelial cells were highlighted with Ulex europaeus agglutinin I (UEA-I) conjugated with peroxidase. UEA-I-stained microvessels were counted at varying levels in the tumour (apex, centre and base) without knowledge of patient outcome. Patients with (n = 30) and without (n = 33) metastases had similar total vessel counts (P = 0.31). There was no evidence of greater vessel density in tumours that had metastasized, by level within the tumour. Similar results were obtained in multivariate analyses. Findings of this study suggest that tumour microvessel density is unrelated to patient survival in uveal melanoma.

Constitutional alterations in p16 in patients with uveal melanoma

Chromosome 9p21 contains a susceptibility gene for cutaneous melanoma. Recent studies suggest that the gene responsible may be CDK41, since it encodes a putative cell cycle inhibitor, p16, and is frequently lost or rearranged in melanoma cell lines. In this study we examined whether germline alterations in CDK41 could be identified in patients with melanoma of the uveal tract. From an archive of bloods collected from patients with uveal melanoma, we identified 13 samples drawn from patients with a history in a family member of uveal (n = 6) or cutaneous (n = 7) melanoma. An additional 24 'control' bloods (without melanoma or any other primary malignancy in a family member), similar to the 'cases' in age and number of first-degree relatives, were also selected for study. For each sample, DNA was extracted from the red blood cell fraction. Using the polymerase chain reaction-single strand conformation polymorphism method, we screened for alterations in p16. Specific changes were characterized by DNA sequencing. Six nucleotide changes were detected in five (13.5%) of the 37 samples examined. An altered gene was found in one (7.7%) of the 13 patients with a family history (of intra-ocular melanoma) and four (16.7%) of the 24 patients with no family history (P = 0.64) of melanoma. In this series the group with a positive family history was predominantly female and most pedigrees involved matrilineal descent. In these data prevalence of germline alteration in p16 was similar in familial and sporadic cases. The results provide evidence against a significant role for p16 in familial clustering of intra-ocular and cutaneous melanomas.

Prospective study of regular aspirin use and the risk of breast cancer

BACKGROUND

Evidence suggests that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) can inhibit tumor development in the large bowel. An inverse association between the use of NSAIDs and the incidence of breast cancer has been observed, but this association has not been statistically significant in all studies.

PURPOSE

We analyzed data from the prospective Nurses' Health Study to evaluate the influence of aspirin use on breast cancer risk.

METHODS

We studied a population of 89,528 female registered nurses who reported no history of breast or other cancers (excluding nonmelanoma skin cancer) and who returned a mailed questionnaire in 1980 that elicited information concerning breast cancer risk factors and current and past aspirin use. Follow-up questionnaires were mailed to the participants every 2 years; the women were followed through 1992. Information concerning current aspirin use was obtained from each biennial questionnaire, except in 1986. Cases of breast cancer were identified through questionnaire responses, and permission was sought for a review of medical records to confirm the diagnoses. Our analysis was based on 2414 cases of invasive breast cancer, which included 2303 cases confirmed with medical records and 111 cases for which no records were obtained. Relative risks (RRs) with 95% confidence intervals (CIs), adjusted for age or age plus other known or potential breast cancer risk factors (i.e., multivariate), were calculated.

RESULTS

Regular aspirin use (two or more tablets per week) in 1980 was unrelated to breast cancer incidence during the succeeding 12-year period (with no regular aspirin use as the referent, multivariate RR = 1.03; 95% CI = 0.95-1.12). The corresponding risk estimate for consistent regular aspirin use during the period from 1980 through 1988 was 1.01 (95% CI = 0.80-1.27). The risks were similar for heavy aspirin use (for more than two tablets per day [i.e., > 14 per week] in 1980 and in 1980 through 1988, the multivariate RRs [95% CIs] were 1.05 [0.89-1.23] and 1.09 [0.75-1.60], respectively) and for extended durations of regular use (e.g., for 20 years or more of regular use, multivariate RR = 1.00; 95% CI = 0.71-1.41).

CONCLUSION

Our results indicate that regular aspirin use does not reduce the risk of breast cancer.

Jewish religion and risk of breast cancer

BACKGROUND

The excess risk of breast cancer among Jewish women has been attributed to the effects of difference in lifestyle and reproductive patterns, but there is now evidence that Jewish women may be more likely than other women to inherit mutations in breast-cancer genes. We investigated whether any excessive risk among Jewish women is confined to those with a family history of breast cancer.

METHODS

We assessed the effect of Jewish religion on breast cancer in a large population-based case-control study (6611 women with breast cancer and 9026 controls) in USA. Participants were given telephone interviews and asked about known and suspected risk factors for breast cancer.

FINDINGS

Overall, Jewish women had only a slightly raised relative risk of breast cancer (1.10 [95% CI 0.84-1.44]; p=0.49). However, the relative risk was much higher for Jewish women with a first-degree relative who had breast cancer (3.78 [1.74-8.16]; p<0.001). The effect of family history was greater in Jewish women than in women of other religions (p interaction = 0.05).

INTERPRETATION

These results are consistent with data suggesting that certain groups of Jewish women have a higher than expected rate of mutation in the breast-cancer gene BRCA1.

Aspirin and the risk of colorectal cancer in women

BACKGROUND

Most data suggest that the regular use of aspirin reduces the risk of colorectal cancer, but some apparently conflicting evidence exists. The effects of the dose and the duration of aspirin consumption on the risk of colorectal cancer are not well understood.

METHODS

We determined rates of colorectal cancer according to the number of consecutive years of regular aspirin use (defined as two or more tablets per week) among women in the Nurses' Health Study who reported regular aspirin use on three consecutive questionnaires (1980, 1982, and 1984) and compared the rates in this group with the rates among women who said they did not use aspirin. Cases of cancer occurring from 1984 through 1992 (the eight years after the 1984 questionnaire) were included.

RESULTS

From 1984 through 1992, we documented 331 new cases of colorectal cancer during 551,651 person-years of follow-up. Women who consistently took two or more aspirin tablets per week had no appreciable reduction in the risk of colorectal cancer as compared with nonusers after four years (relative risk, 1.06; 95 percent confidence interval, 0.78 to 1.45) or after five to nine years (relative risk, 0.84; 95 percent confidence interval, 0.55 to 1.28). There was a slight reduction in risk among women who took aspirin for 10 to 19 years, but it was not statistically significant (relative risk, 0.70; 95 percent confidence interval, 0.41 to 1.20). However, there was a statistically significant reduction after 20 years of consistent use of aspirin (relative risk, 0.56; 95 percent confidence interval, 0.36 to 0.90; P for trend = 0.008). The maximal reduction in risk was observed among women who took four to six tablets per week; higher doses had a similar apparent benefit. Controlling for risk factors for colorectal cancer, including diet, did not change the results, and the earlier diagnosis and removal of colorectal adenomas among aspirin users did not account for the results.

CONCLUSIONS

Regular aspirin use, at doses similar to those recommended for the prevention of cardiovascular disease, substantially reduces the risk of colorectal cancer. However, this benefit may not be evident until after at least a decade of regular aspirin consumption.

Lens changes after proton beam irradiation for uveal melanoma

PURPOSE

Because limited data exist on the incidence of lens changes after therapeutic intraocular irradiation, we studied a group of patients who underwent proton irradiation for uveal melanoma, in order to estimate cumulative rates of radiation-induced posterior subcapsular opacities and age-related lens changes at specific time points. after irradiation.

METHODS

Cumulative rates for each type of opacity were estimated from among the 383 patients, treated between 1987 and 1989, who had clear lenses or minimal lens changes before irradiation. Cox's proportional hazards model was used to evaluate the independent effects of tumor and treatment-related characteristics on the development of posterior subcapsular opacities in these patients. Risk factors for posterior subcapsular opacities were evaluated.

RESULTS

By three years after irradiation, posterior subcapsular opacities had developed in 42% of the patients, and rates increased significantly with lens dose and with tumor height. The risk of posterior subcapsular opacities was over three times higher when the lens received a substantial dose of irradiation (adjusted relative risk, 3.25; 95% confidence interval, 1.60-6.59), as compared with minimal dose, and was three times higher when the tumor was highly elevated (adjusted relative risk, 3.05; 95% confidence interval, 1.45-6.40) as compared with minimally elevated lesions. Opacities in the other segments of the lens were age related.

CONCLUSIONS

These data show that patients receiving therapeutic intraocular irradiation have a high risk of developing posterior subcapsular opacities. As expected, the leading risk determinant of posterior subcapsular change is the amount of irradiation received by the lens.

Familial uveal melanoma

Because familial occurrences of uveal melanoma are rare, there have only been 15 cases of familial melanoma reported in the literature. We studied 11 additional families with a total of 24 members, in which two or more members were afflicted with uveal melanoma. The median age at diagnosis was 56.5 years, similar to the median age at diagnosis of the remaining patients treated in our institution. Thirteen were male and 11 were female, which is consistent with the slight predominance of males found in many large surveys of patients with uveal melanoma. There is a possibility of a heritable component present in these families.

The time course of irradiation changes in proton beam-treated uveal melanomas

BACKGROUND

Although histopathologic changes in uveal melanomas treated by irradiation have been well characterized, the timing of these effects after irradiation has not been previously evaluated.

METHODS

The series consisted of a total of 92 eyes with uveal melanoma, enucleated at various intervals after proton irradiation (range, 1 month to 8 years) due to complications (n = 66) or tumor growth (n = 22), or at autopsy (n = 4). Study slides were read, using a standard protocol, by two pathologists masked to the timing of the enucleation after irradiation and the reason for the surgery.

RESULTS

The prevalence of inflammation decreased whereas fibrosis increased with time from 15% of cases enucleated within 12 months (early cases) to 61% of those enucleated more than 30 months (late cases) after irradiation (P for trend = 0.0005). Tumor necrosis and blood vessel damage occurred early, and the prevalence of these changes was constant over time. Excluding tumors with evidence of growth after irradiation, mitotic figures became progressively less common as the interval between irradiation and enucleation increased (P for trend = 0.015); no mitotic figures were present in 40 high-power fields more than 30 months after irradiation.

CONCLUSION

Histopathologic changes in irradiated melanomas vary according to the time elapsed since irradiation. Inflammation decreases with time whereas fibrosis becomes more prevalent with time after irradiation. Among controlled tumors, mitotic figures appear only in recently irradiated tumors.

An evaluation of the influence of reproductive factors on the risk of metastases from uveal melanoma

BACKGROUND

There is a paucity of data concerning the possible role played by hormonal factors in the risk of metastases from intraocular melanomas.

METHODS

The authors studied the influence of post-diagnosis pregnancy and oral contraceptive use in a group of women of reproductive age (45 or younger) who were treated for uveal melanoma by proton beam irradiation. A baseline reproductive history had been collected before irradiation for all women, and interim reproductive data were collected by mailed questionnaire.

RESULTS

In this age group, the overall rate of metastasis among women was similar to that of men treated during the same interval (adjusted rate ratio: 1.28; 95% confidence interval: 0.62-2.67). A total of 24 full-term pregnancies were reported among the 139 women still menstruating at diagnosis. Twenty-three women reported regular oral contraceptive use. Metastases developed in 15 of the 139 women. Compared with other women in the series, rates of metastases were not higher among the women who reported pregnancies (P = 0.932) or oral contraceptive use (P = 0.424) after diagnosis.

CONCLUSION

Although based on limited numbers, results suggest that the hormonal environment has no appreciable influence on risk of metastases in younger women with uveal melanoma.

Hormone replacement therapy and risk of breast cancer: results from epidemiologic studies

OBJECTIVE

We combined data from published reports of the relation between estrogen use and breast cancer. We specifically addressed the hypothesis that the addition of progestins to estrogen therapy reduces the risk of breast cancer.

STUDY DESIGN

A meta-analysis was performed.

RESULTS

Replacement hormone therapy is not associated with increased risk of breast cancer in women who have ever used it (relative risk 1.02, 95% confidence interval 0.93 to 1.12). However, current use is associated with increased risk (relative risk 1.40, 95% confidence interval 1.20 to 1.63). Although there was no significant trend with increasing duration of use, women with > or = 10 years of estrogen use had a relative risk of 1.23 (95% confidence interval 1.08 to 1.40). However, data on use of estrogen plus progestins combined from four studies indicate that risk is not reduced and that the overall relative risk is 1.13 (95% confidence interval 0.78 to 1.64). Further, risk did not vary in strata of family history or benign breast disease.

CONCLUSION

Although these results exclude a large effect of hormone therapy on risk of breast cancer, we are unable to rule out some risk associated with current or long-term estrogen use.

Asymmetric distribution of arteriovenous crossings in the normal retina

BACKGROUND

Recently, there has been renewed interest in the orientation of the crossing retinal vessels at arteriovenous intersections, particularly as it relates to the risk of branch vein occlusion. Little is known about the distribution of the two types of crossings in the normal retina.

METHODS

The authors studied standard fundus photographs of 51 subjects without retinal disease. Arteriovenous crossings were analyzed for fundus location and relative orientation of the crossing vessels (vein-posterior or vein-anterior).

FINDINGS

In the superotemporal quadrant, crossings were distributed closer to the optic disc (P < 0.001), and a greater proportion of crossings were vein-posterior (P = 0.01) than in the inferotemporal quadrant. As a result, within a 3-disc diameter (DD) radius of the optic disc, there were significantly more vein-posterior crossings in the superotemporal than in the inferotemporal quadrant (P < 0.001).

CONCLUSION

These findings further define normal retinal vascular anatomy and may explain the predilection for branch retinal vein occlusions to occur in the superotemporal quadrant.

Occupation and risk of uveal melanoma. An exploratory study

BACKGROUND

Little is known about the cause of uveal melanoma, the most common primary intraocular malignant lesion in adults. This population-based case-control study evaluated occupational exposures.

METHODS

One hundred ninety-seven newly diagnosed cases of uveal melanoma participated. Approximately two control subjects matched for age, sex, and telephone exchange area were selected for each case by random-digit dialing. Data were collected by a structured telephone interview. Two systems of occupational coding were used: an occupation-exposure linkage system and the Bureau of Census data. Conditional logistic regression for matched studies was used to examine various occupational exposures while controlling for previously reported potential confounders and for family income. The occupation-exposure matrix was used to define clusters of cases exposed to a particular chemical group from various occupations.

RESULTS

Odds ratios were elevated for agriculture and farming work for both industry and occupation; this was consistent across both classification systems. Elevated odds ratios also were found for occupations involving machine operations, fabrication, assembling, equipment cleaning, and exposure to metal industries. Exposure to alkylating agents and phenols was associated with a lower risk compared with all other exposures. Several self-reported exposures also were studied. Exposures associated with elevated odds ratios were inks, insecticides, gases, radioactive substances, polybromated biphenyls, and chemical solvents.

CONCLUSIONS

This exploratory study suggests various occupational associations for uveal melanoma and areas for future research.

Nucleolar organizer regions in iris nevi and melanomas

The silver staining of nucleolar organizer region-associated proteins is an objective method that has been used to differentiate benign from malignant neoplasms. Recently this method was used to distinguish benign choroidal nevi from malignant choroidal melanomas. We studied 24 iris melanocytic lesions to assess the applicability of this technique for differentiating benign from neoplastic iris tumors. Masked observers determined the number of silver-stained nucleolar organizer region dots per cell for silver-stained specimens. Iris nevi contained a mean of 1.6 silver-stained nucleolar organizer region dots per cell, whereas iris (spindle A and B, spindle B, epithelioid, mixed cell) malignant melanomas contained a mean of at least 3.5 silver-stained nucleolar organizer region dots per cell (P less than .0001). All iris nevi demonstrated counts lower than 1.9, whereas all iris melanomas demonstrated counts greater than 2.8. Silver-stained nucleolar organizer region counts were also compared with the clinicopathologic variables of gender, age, and largest specimen dimension. Only the largest specimen dimension correlated with silver-stained nucleolar organizer region counts (P less than .0029). The silver-stained nucleolar organizer region method is a simple technique for differentiating iris nevi from iris melanomas. The silver-stained nucleolar organizer region technique may aid in the assessment and treatment of iris lesions by confirming the malignancy of biopsy specimens.

Radiation maculopathy after proton beam irradiation for choroidal melanoma

PURPOSE

Radiation maculopathy is a microangiopathy of the retina, which is often observed after irradiation of the eye. To quantitatively determine the frequency of anatomic and functional features of this condition, the authors reviewed a large series of patients with choroidal melanomas who were treated by proton beam irradiation.

METHODS

Color photographs and/or fluorescein angiograms of 218 patients with paramacular choroidal melanomas were graded by two independent masked readers to determine the frequency of the various lesions of radiation maculopathy.

RESULTS

Overall, 194 (89%) of the 218 patients in this study developed some degree of radiation maculopathy. The earliest and most common finding was macular edema, which was observed in 87% of patients, overall, by the end of year 3. Microvascular changes (microaneurysms and/or telangiectasia), intraretinal hemorrhages, and capillary nonperfusion were noted in 76%, 70%, and 64% of eyes, respectively, by the end of postirradiation year 3. Visual acuity was retained at 20/200 or better in 90% of eyes 1 year after irradiation and in 67% of eyes 3 years after treatment.

CONCLUSION

Radiation maculopathy is common after proton beam irradiation of paramacular choroidal melanomas. However, ambulatory vision is preserved in many eyes.

Histopathology of proton beam-irradiated vs enucleated uveal melanomas

The histopathology of eyes with uveal melanoma was compared in a masked fashion in 47 eyes whose primary treatment was enucleation and a matched series of 47 eyes enucleated after proton beam irradiation. Irradiated tumors were more likely to show signs of necrosis (P less than .001) and fibrosis (P = .005) and to have balloon cells present (P = .002). In the irradiated group, mitotic figures were fewer in 40 high-power fields (P = .020), and the prevalence of tumor blood vessel damage (P less than .001) was higher. Changes in the retina were more common in the irradiated series, but damage was usually overlying or in close proximity to the tumor. Based on characteristic changes, the pathologist distinguished irradiated from nonirradiated eyes in 85% of the cases. These findings suggest that irradiation damages tumor cells and blood vessels, and alters the tumor's capacity for cellular reproduction.