The relationship between prognostic factors of breast cancer and thyroid disorders in Turkish women

[Hyperthyroidism and breast cancer: Is there a link?]

The objective of this review was to determine whether there is an association between hyperthyroidism and the risk of developing a breast cancer from the analysis of data in the literature.

METHOD

The analyzed articles were extracted from the PUBMED database from 2002 to 2017 using the following keywords "hyperthyroidism AND breast cancer" and "thyroid AND breast cancer".

RESULTS

A total of 22 studies were selected, including 8 cohort studies, 12 case-control studies and 2 meta-analyzes. Of these 22 studies, 15 have established a significant epidemiological or biological link between hyperthyroidism and breast cancer. Five of them were particularly interested in Graves' disease, and four demonstrated a positive association between this disease and the onset of breast cancer, especially within three years from the thyropathy diagnosis. These different studies also highlighted the increased risk of breast cancer seen in overweight or postmenopausal women. Contradictions persist over the types of mammary cancers observed and their prognosis.

CONCLUSION

This review reveals that women with hyperthyroidism appear to have a moderately high risk of breast cancer (RR<2). These data are corroborated by solid physiopathological hypotheses. Regardless of the type of thyropathy responsible for hyperthyroidism, care should be taken to ensure that these patients receive a clinical examination of the breasts on an annual basis and mammographic screening every 2 years from the age of 50 years.

Thyroid disorders and mammographic density in Spanish women: Var-DDM study

OBJECTIVES

The association between breast cancer (BC) and thyroid disorders has been widely explored with unclear results. Mammographic density (MD) is one of the strongest risk factor for BC. This study explores the relationship between thyroid diseases and MD in Spanish women.

MATERIALS & METHODS

This cross-sectional study covered 2883 women aged 47-71 years participating in 7 BC screening programs in 2010. They allowed access to their mammograms, had anthropometrical-measures taken, and answered a telephonic epidemiological interview which included specific questions on thyroid diseases. Percentage of MD was assessed with a semiautomatic-computer tool (DM-scan) by two trained radiologists. We calculated the geometric mean of MD percentages (mean MD). Multivariable mixed linear regression models with random screening-center-specific intercepts were fitted, using log-transformed percentage of MD as dependent variable and adjusting for age, body mass index, menopausal status and other confounders. e^β represents the relative increase of mean MD.

RESULTS

13.9% of the participants reported personal history of thyroid disease. MD was not associated to hyperthyroidism (e^β:1.05, 95%CI: 0.82-1.36), hypothyroidism (e^β:1.02, 95%CI: 0.75-1.38), thyroid nodules (e^β:1.01, 95%CI: 0.85-1.19) or thyroid cancer (e^β:1.03, 95%CI: 0.56-1.92). However, women with goiter had lower MD (mean MD_no-goiter: 13.4% vs mean MD_goiter: 10.6%; e^β:0.79, 95%CI: 0.64-0.98) and those with Hashimoto thyroiditis had higher MD (mean MD_{no-thyroiditis}: 13.3% vs mean MD_thyroidits: 25.8%; e^β:1.94, 95%CI: 1.00-3.77).

CONCLUSION

Functional thyroid disorders were not related to MD. However, MD was lower in women with goiter and higher in those reporting Hashimoto's thyroiditis. These relationships should be confirmed in future studies.

STUDY OF THE PREVALENCE OF AUTOIMMUNE THYROID DISEASE IN WOMEN WITH BREAST CANCER

OBJECTIVE

The aim of this study was to analyze the prevalence of thyroid disorders in patients with a positive biopsy for breast cancer prior to specific antitumor treatment.

METHODS

The frequency and pattern of thyroid disorders were evaluated in 112 patients with breast cancer (G1) and 125 control patients (G2) by analyzing serum thyroid-stimulating hormone (TSH), anti-thyroid peroxidase antibodies, and anti-thyroglobulin antibodies. In addition, the expression of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2) was assessed in the breast biopsies by immunohistochemistry.

RESULTS

The frequency of thyroid disorders, such as changes in TSH levels and/or the presence of thyroid antibodies, was not different between the 2 groups examined (30.4% in G1 versus 28.0% in G2) (P = .69). However, a family history of thyroid disease was more frequent in patients with breast cancer (50.5% in G1 versus 28.2% in G2) (P = .001). Regarding the clinical stage of breast cancer, there was no difference between women with autoimmune thyroiditis and those without thyroid dysfunction (P = .316). Similarly, there were no differences in hormone receptor (estrogen or progesterone) and HER2 expression between patients who tested positive and those who tested negative for anti-thyroid antibodies (P = .052 and P = .549, respectively).

CONCLUSION

The data obtained in this study did not reveal a higher frequency of autoimmune thyroid disease in patients with breast cancer compared to controls. A family history of thyroid disease was more common in those with breast cancer.

The risk of second primary malignancy is increased in differentiated thyroid cancer patients with a cumulative (131)I dose over 37 GBq

BACKGROUND

The aim of this study was to investigate the risk factors for second primary malignancy (SPM) diagnosed after differentiated thyroid cancer (DTC).

METHODS

A total of 2468 DTC patients who underwent thyroidectomy were reviewed. SPM was defined as a non-thyroidal malignancy, diagnosed at least 1 year after the diagnosis of thyroid cancer. Patients were divided into five groups according to cumulative (131)I dose: very high-activity (≥ 37.0 GBq), high-activity (22.3-36.9 GBq), intermediate-activity (5.56-22.2 GBq), low-activity (1.1-5.55 GBq) and no RAI.

RESULTS

Among the 2468 patients, 61 (2.5%) had SPMs during 7.0 (1.0-33.0) years of median follow-up. Age above 40 years, male sex and very high-activity RAI were independent risk factors for the development of SPM. SPM-related mortality was highest in the very high-activity group, while DTC-related mortality was highest in the high-activity group. The overall mortality both from SPM and DTC was highest in the high-activity group.

CONCLUSION

A cumulative (131)I dose <37.0 GBq did not increase the risk of SPM. A cumulative (131) I dose ≥ 37.0 GBq increased the risk of SPM and SPM-related mortality and decreased the DTC-specific mortality, resulting in a similar all-cause mortality compared with the low-activity RAI group. Using repeated high-dose RAI for treating RAI-responsive but persistent DTC patients needs careful consideration of the individual benefits from RAI vs the risk of developing SPM.

SERUM THYROTROPIN CONCENTRATIONS ARE NOT PREDICTIVE OF AGGRESSIVE BREAST CANCER BIOLOGY IN EUTHYROID INDIVIDUALS

OBJECTIVE

The potential influence of hypothyroidism on breast cancer remains incompletely understood. The objective of this study was to investigate the relationship between serum thyrotropin (thyroid-stimulating hormone, TSH) concentration and markers of aggressive breast cancer biology as defined by receptor expression profile, tumor grade, and American Joint Committee on Cancer (AJCC) stage characteristics.

METHODS

This was a retrospective cohort study of patients from 2002 to 2014. All breast cancer patients who had complete receptor (estrogen receptor, ER; progesterone receptor, PR; and human epidermal growth factor receptor 2, Her2/neu) and prediagnosis serum TSH data (n = 437) were included. All patients had 1 of 6 receptor profiles: ER+ PR+ Her2/neu-, ER+ PR- Her2/neu-, ER+ PR+ Her2/neu+, ER+ PR- Her2/neu+, ER- PR- Her2/neu+, or ER- PR- Her2/neu-. Log-transformed serum TSH concentrations were analyzed using multinomial and logistic regressions to identify potential relationships with markers of breast cancer aggressiveness.

RESULTS

Increasing serum TSH concentration was associated with a lower probability of having the receptor expression profile ER+ PR+ Her2/neu+ compared to patients with the ER+ PR+ Her2/neu- profile (odds ratio [OR] = 0.52, P = .0045). No significant associations between other receptor expression profiles and serum TSH concentration were found. All time-weighted and unweighted median serum TSH concentrations were within normal limits. No significant associations between serum TSH concentration and tumor grade, overall AJCC stage, tumor size (T), lymph node positivity (N), or presence of metastasis (M) were observed.

CONCLUSIONS

Serum TSH was not associated with markers of breast cancer aggressiveness in our cohort.

Relationship between breast cancer and levels of serum thyroid hormones and antibodies: a meta-analysis

The breast and the thyroid are hormone responsive organs that are closely related with changes of endocrine function and glandular disease. An association between thyroid disorders and breast cancer (BC) risk has been suggested, although the results are inconclusive. The purpose of the present study was to summarize evidence supporting a relationship between BC and the level of thyroid hormones and antibodies. The MEDLINE and EMBASE electronic databases were searched for studies published between 2000 and 2014. The pooled effects were presented as weighted mean differences (WMD) with 95% confidence intervals (CI) using fixed or random effect models. We summarized the results of 8 cross-sectional studies with 4, 189 participants. The overall pooled results showed that the levels of FT3 and FT4 were significantly increased in patients with BC (WMD=1.592 pmol/l; 95% CI: 0.15-3.033 and WMD=0.461 ng/dl; 95% CI: 0.015-0.906; p=0.043). The TPOAb level in patients with BC was higher than that in the control group (WMD=81.4 IU/ml; 95% CI: 78.7-84.0; p=0.000). The overall pooled results of the TgAb with random effects analyses showed that the TgAb level was significantly increased in patients with BC (WMD=101.3 IU/ml; 95% CI: 48.7-153.9; p=0.000). The present results indicated that the serum levels of FT3, TPOAb and TgAb are significantly higher in patients with breast cancer than in healthy controls.

Autoimmune Thyroid Disease and Breast Cancer Prognosis

OBJECTIVE

The association of breast cancer and thyroid autoimmunity has been suggested by many studies in the literature, but the causality still needed to be proven. With this study we aimed to search the correlation between thyroid autoimmunity and breast cancer prognostic factors.

MATERIALS AND METHODS

To this prospective cohort study 200 consecutive breast cancer patients, who were operated in our clinic were included. Patients' serum thyroid hormone, anti-thyroglobuline (anti-TG) and anti-thyroid peroxidase (anti-TPO) levels and tumors' prognostic parameters (tumor size, axillary involvement, histological grade, lymphovascular invasion, receptor status, Ki-67 proliferation index) were collected. The correlation between serum thyroid autoantibody levels and tumor's prognostic factors were studied.

RESULTS

The prevalence of thyroid autoimmunity (high levels of serum anti-TPO and/or anti-TG) was 18.5% (n=37). Patients with thyroid autoimmunity had a significant lower rate of axillary involvement and a lower rate of Ki-67 proliferation index (22% vs. 46% [p=0,007] and 12.73% vs. 20.72% [p=0.025], respectively) and were more commonly included to the "low-risk" group (<14%) according to their Ki-67 scores (68% vs. 46%; p=0.015). Other parameters did not differ between the two groups.

CONCLUSION

We found a favorable correlation between thyroid autoimmunity and axillary involvement and also Ki-67 proliferation index score, which are two crucial and strongly predictive parameters of breast cancer prognoses. This supports the idea of thyroid autoimmunity being a favorable prognostic parameter. Further studies are necessary to investigate the reasons of protective or predictive effect of high thyroid peroxidase levels in breast cancer patients.

T3 levels in relation to prognostic factors in breast cancer: a population-based prospective cohort study

BACKGROUND

The issue of a potential association between thyroid conditions/hormones and breast cancer has been studied extensively during the last decades but the results have been inconclusive and almost no studies have investigated breast cancer aggressiveness. We have previously found a positive association between prospectively measured levels of triiodothyronine (T3) and breast cancer incidence as well as breast cancer mortality. We now investigated prediagnostic T3 levels in relation to specific prognostic factors in breast cancer.

METHODS

The Malmö Preventive Project is a population-based prospective cohort including 2185 women in whom T3 levels were measured at baseline. That is, total T3 levels were measured before a potential diagnosis of breast cancer. Mean follow-up was 23.3 years and 149 women in the study population were diagnosed with invasive breast cancer. Tumours were classified according to selected prognostic factors of breast cancer; i.e. grade, tumour size, lymph node metastasis, and hormonal receptor status. T3 was handled both as tertiles and as a continuous variable. A Cox's proportional hazards analysis yielded hazard ratios with 95% confidence intervals. All analyses were also restricted to postmenopausal women.

RESULTS

Overall there was a statistically significant association between T3 and "all" breast cancers. The adjusted Hazard Ratio (HR) in the third tertile, as compared to the first, was (1.61:1.07-2.43). There was a statistically significant positive association between the third T3 tertile and large tumours, i.e. > 20 mm, (3.17:1.20-8.36) and the occurrence of lymph node metastases, (4.53:1.60-12.83). Other prognostic factors positively associated with T3 were negative oestrogen receptor (ER) status, (3.52:1.32-9.41) and negative progesterone receptor (PGR) status, (3.52:1.42-8.75). The analyses of T3 as a continuous variable and analysis restricted to postmenopausal women, confirmed the results but also showed an association with smaller tumours and in postmenopausal women a contemporary association with negative lymph nodes.

CONCLUSIONS

This prospective study of serum T3 levels in relation to breast cancer aggressiveness is the first of its kind. We found statistically significant positive associations between higher prediagnostic T3 levels and larger tumours, occurrence of lymph node metastases, and negative ER and PGR status.

Cancer risk in patients with Graves' disease: a nationwide cohort study

BACKGROUND

The possibility of an association of Graves' disease (GD) with subsequent cancers has been previously reported.

METHODS

Our study used the Taiwanese National Health Insurance Research Database (NHIRD), which identified 5025 newly diagnosed GD patients from 1997 to 2010, and 20,100 frequency matched non-GD patients. The risk of developing cancer for GD patients was measured using the Cox proportional hazard model.

RESULTS

The incidence of developing cancer in the GD cohort was 4.92 per 1000 person-years and was 1.37-fold higher than in the comparison cohort (p<0.001). Compared with patients aged 20-34 years, older age groups demonstrated a higher risk of developing cancer (35-49 years: hazard ratio (HR)=4.15; 50-64 years: HR=7.39;≥65 years: HR=13.4). After adjusting for sex, age, and comorbidities, the HR for developing breast cancer and thyroid cancer was 1.58- and 10.4-fold higher for patients with GD. Furthermore, the incidence rates (IRR) were the highest in the first three years: 2.06 [confidence interval (CI)=1.87-2.27] and 15.6 [CI=13.9-17.5] in breast cancer and thyroid cancer with GD respectively. Specifically, a 16-fold hazard of developing thyroid cancer was present in the first three years in the GD cohort compared to the non-GD cohort [CI=7.95-32.1].

CONCLUSIONS

GD patients have a higher risk of cancer, particularly thyroid and breast cancer sequent within six and three years respectively. Strategies for preventing thyroid and breast cancer are proposed.

Prospectively measured thyroid hormones and thyroid peroxidase antibodies in relation to breast cancer risk

Thyroid hormones influence both normal breast cell differentiation and breast cancer cell proliferation and stimulate the angiogenesis of certain cancer forms. Several cross-sectional studies have measured thyroid hormones/autoantibodies in breast cancer ceases vs. controls, but it is difficult to determine the cause-effect direction in these studies. Only three prospective studies have reported on the subject so far. The aim of our study was to investigate prediagnostically measured levels of thyroid hormones, thyrotropin (TSH) and thyroid autoantibodies in relation to subsequent risk of breast cancer. The Malmoe Diet and Cancer study examined 17,035 women between 1991 and 1996. Blood samples were collected at baseline and free triiodothyronine (T3), free thyroxin (T4), TSH and thyroid peroxidase autoantibodies (TPO-Ab) levels were measured in 676 cases and 680 controls. Relative risks with 95% confidence intervals were assessed using a logistic regression analysis adjusted for potential confounders. Free T4 levels were positively associated with a high risk of breast cancer, and the OR for women with free T4 levels above vs. below the median was 1.40 (1.10-1.77). This association was most pronounced in overweight women (1.51:1.07-2.12). Women with high levels of TPO-Ab had a lower risk of breast cancer, but only the analysis of TPO-Ab as a continuous variable reached statistical significance. Free T4 was in our study positively associated with a high risk of breast cancer. This association was most pronounced in overweight/obese women. Women with a high level of TPO-Ab had a relatively low risk of breast cancer.

Benign thyroid disease is associated with breast cancer: a meta-analysis

The controversial relationship between benign thyroid diseases and breast cancer (BC) has been investigated for over 50 years. Despite extensive population studies, the results as a whole have been inconsistent. The purpose of this study was to collate and analyse available data, calculating a pooled odds ratio (OR) of the risk of BC in patients diagnosed with benign thyroid diseases. Studies were obtained from a database search of MEDLINE, EMBASE, PubMed, Current Contents Connect and Google Scholar with additional cross checking of reference lists. Inclusion criteria required a confirmed diagnosis of a benign thyroid disease, reporting of an OR or data to calculate an OR (and 95% confidence interval, CI) and the use of an internal control group as the comparator. Collated data was assessed for heterogeneity and a pooled OR calculated. 28 studies were included in the meta-analysis. There was significant evidence of an increased risk of BC in patients with autoimmune thyroiditis, evident in a pooled OR 2.92 (95% CI 2.13-4.01). In addition, the results supported an increased risk associated with the presence of anti-thyroid antibodies (OR 2.02, 95% CI 1.63-2.50) and goitre (OR 2.26, 95% CI 1.39-3.69). Subgroup analysis of antibody presence revealed increased risk associated with both anti-TPO (OR 2.64, 95% CI 1.82-3.83) and anti-TG (2.71, 95% CI 1.58-4.69). Quantitative analysis of hypothyroidism and hyperthyroidism was not significant. While these results indicate an association between thyroid auto-immunity and BC, further prospective studies are required to definitively prove causality.

Risk factors and a predictive model for thyroid cancer in Korean women

BACKGROUND

Thyroid cancer incidence in Korean women has increased radically and is the highest in all cancer types. However, the rate of cancer screening among women is very low.

OBJECTIVE

The aim of the study was to determine the risk factors for thyroid cancer and to develop a predictive model based on these risk factors.

METHODS

The study design comprised a literature review and a case-control study. To construct a predictive model, the participants selected were 260 female outpatients diagnosed with malignant neoplasm of thyroid gland who had undergone thyroid removal surgery. A total of 259 people for the control group were selected by adopting a 5-year age-matching method.

RESULTS

From the literature review, 6 categories of risk factors were identified. Nine variables, including occupation, live(d) in coastal region, family history of thyroid cancer, history of benign thyroid tumor, menopause status and weight gain, number of full-term deliveries, abortion, exercise intensity, and stress, remained as statistically significant risk factors in the stepwise regression model. Regarding the predictive power of the model, the area under the receiver operating characteristic curve was .79, accuracy was .77, sensitivity was .89, specificity was .65, positive predictive value was .72, and negative predictive value was .85.

CONCLUSION

The predictive power of the model was relatively good, so it can be used to identify individuals at high risk for thyroid cancer.

IMPLICATIONS FOR PRACTICE

The predictive model can be used in promoting to participate in early cancer-screening tests. Thus, it will be possible to detect thyroid cancer in its earliest stage, diminish mortality, and improve quality of life.

Prospectively measured triiodothyronine levels are positively associated with breast cancer risk in postmenopausal women

Introduction

The potential association between hypo- and hyperthyroid disorders and breast cancer has been investigated in a large number of studies during the last decades without conclusive results. This prospective cohort study investigated prediagnostic levels of thyrotropin (TSH) and triiodothyronine (T3) in relation to breast cancer incidence in pre- and postmenopausal women.

Methods

In the Malmö Preventive Project, 2,696 women had T3 and/or TSH levels measured at baseline. During a mean follow-up of 19.3 years, 173 incident breast cancer cases were retrieved using record linkage with The Swedish Cancer Registry. Quartile cut-points for T3 and TSH were based on the distribution among all women in the study cohort. A Cox's proportional hazards analysis was used to estimate relative risks (RR), with a confidence interval (CI) of 95%. Trends over quartiles of T3 and TSH were calculated considering a P-value < 0.05 as statistically significant. All analyses were repeated for pre- and peri/postmenopausal women separately.

Results

Overall there was a statistically significant association between T3 and breast cancer risk, the adjusted RR in the fourth quartile, as compared to the first, was 1.87 (1.12 to 3.14). In postmenopausal women the RRs for the second, third and fourth quartiles, as compared to the first, were 3.26 (0.96 to 11.1), 5.53 (1.65 to 18.6) and 6.87 (2.09 to 22.6), (P-trend: < 0.001). There were no such associations in pre-menopausal women, and no statistically significant interaction between T3 and menopausal status. Also, no statistically significant association was seen between serum TSH and breast cancer.

Conclusions

This is the first prospective study on T3 levels in relation to breast cancer risk. T3 levels in postmenopausal women were positively associated with the risk of breast cancer in a dose-response manner.

Possible DNA viral factors of human breast cancer

Viruses are considered to be one of the high-risk factors closely related to human breast cancer. However, different studies of viruses in breast cancer present conflicting results and some of these works remain in dispute. DNA viruses, such as specific types of human papillomaviruses (HPV), Epstein–Barr virus (EBV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), and human herpes virus type 8 (HHV-8), have emerged as causal factors of some human cancers. These respective exogenous viruses and the possibility of multiple viral factors are discussed in this review.

Autoimmune hypothyroidism and breast cancer in the elderly

PURPOSE

To determine whether autoimmune hypothyroidism (AIHT) influences breast cancer (BRCA) incidence or all-cause survival.

METHODS

Administrative data were used to identify elderly women living in Ontario, Canada with and without AIHT based on prescriptions for levothyroxine (LT4) (N = 178,186). Women were followed from April 1, 1994-March 31, 2003 for BRCA outcomes.

RESULTS

The incidence of BRCA was similar in LT4 users and a propensity-matched cohort of non-users (adjusted HR = 0.99; 95% CI: 0.92-1.07). All-cause mortality was significantly lower in LT4 users compared to non-users (HR 0.95; 95% CI: 0.93-0.97, P < 0.001), as was all-cause mortality following BRCA diagnosis (HR 0.87; 95% CI: 0.77-0.98, P = 0.02).

CONCLUSIONS

LT4 use, as a surrogate for AIHT, is not a risk factor for BRCA in elderly women. The small survival advantage noted among LT4 users who developed BRCA likely represents a 'healthy user' effect. Further study is needed to investigate whether autoimmunity in general is related to BRCA development or related outcomes.

The incidence of second primary tumors in thyroid cancer patients is increased, but not related to treatment of thyroid cancer

OBJECTIVE

The aim of the present study is to assess the prevalence of second primary tumors in patients treated for thyroid cancer. Furthermore, we wanted to assess the standardized risk rates for all second primary tumors, but especially for breast cancer, as data in the literature indicate an excessive risk in differentiated thyroid cancer (DTC) patients for this tumor.

MATERIALS AND METHODS

We included consecutive patients, who received ablation treatment with I-131 at the Leiden University Medical Center between January 1985 and December 1999 (n = 282). The mean period of follow-up was 10.6 +/- 4.1 years.

RESULTS

Thirty-five of the 282 patients (12.4%) had a second primary tumor (SPT), either preceding or following the diagnosis of thyroid cancer. Five other patients had three primary tumors, including DTC. As a result, 40 additional tumors were found in this group, revealing an overall prevalence of 14.2%. Twenty tumors (7.1%) preceded the thyroid cancer with a mean interval of 5.7 years (range: 0.5-22.0 years), whereas 20 tumors (7.1%) occurred after this tumor with a mean interval of 6.7 years (range: 1.0-15.0 years). In 13 female patients, breast cancer was found as SPT. The standardized incidence rate (SIR) for all cancers after the diagnosis of DTC in this study population was not increased (1.13; confidence interval (CI): 0.68-1.69). However, we found an increased SIR of 2.26 (CI: 1.60-3.03) for all cancers either following or preceding DTC, which is mainly caused by a SIR of 3.95 (CI: 2.06-6.45) for breast cancer.

CONCLUSION

Patients with DTC have an overall increased standardized incidence rate for second primary tumors, but not for second primary tumors following I-131 therapy. These findings suggest a common etiologic and/or genetic mechanism instead of a causal relation.

Relationship between viral factors, axillary lymph node status and survival in breast cancer

PURPOSE

Our previous study based on the results of polymerase chain reaction and Southern hybridization for the detection of Human papilloma virus (HPV), Cytomegalovirus (CMV), Epstein-Barr virus (EBV), Herpes simplex virus (HSV)-1, HSV-2, and Human herpesvirus (HHV)-8 DNA in non-familial breast cancer patients suggest that the viruses associated with breast cancer are HHV-8 > EBV (P < 0.01). Therefore, efforts were made to further investigate the association between breast cancer with nodal status and viral infections.

METHODS

Sixty-two breast cancer patients and their mammary specimens were enrolled in this retrospective study. The presence of these six potential oncogenic viruses was analyzed to establish the relationship between nodal status and treatment outcome. Statistical analyses were used for the assessment of variables, including viral positivity and clinical feature.

RESULTS

Viral positivity was not significantly different comparing node-positive and node-negative patients (P > 0.05). When the viral factors were not entered for statistical analyses, no variable was significantly related to overall survival. However, tumor stage, tumor size, nodal status , and estrogen receptor were significantly related to relapse-free survival (P < 0.05). For viral factors, the number of infecting viruses is related to the overall and relapse-free survivals. Only when V0 or V(0, 1) was grouped for comparison with other multiply virus-infected subgroups, were the overall and relapse-free survivals significantly different (P < 0.005 or P < 0.001). The results suggest that HSV-1, HHV-8, EBV, CMV, and HPV were related to overall survival, however, only HHV-8 and CMV were related to relapse-free survival (P < 0.05 or P < 0.01).

CONCLUSION

Virus factor is significantly related to human breast cancer, not only in terms of the oncogenetic process, but also in overall and relapse-free survivals.

Profile of thyroid hormones in breast cancer patients

Estrogen involvement in breast cancer has been established; however, the association between breast cancer and thyroid diseases is controversial. Estrogen-like effects of thyroid hormone on breast cancer cell growth in culture have been reported. The objective of the present study was to determine the profile of thyroid hormones in breast cancer patients. Serum aliquots from 26 patients with breast cancer ranging in age from 30 to 85 years and age-matched normal controls (N = 22) were analyzed for free triiodothyronine (T3F), free thyroxine (T4F), thyroid-stimulating hormone (TSH), antiperoxidase antibody (TPO), and estradiol (E2). Estrogen receptor ss (ERss) was determined in tumor tissues by immunohistochemistry. Thyroid disease incidence was higher in patients than in controls (58 vs 18%, P < 0.05). Subclinical hyperthyroidism was the most frequent disorder in patients (31%); hypothyroidism (8%) and positive anti-TPO antibodies (19%) were also found. Subclinical hypothyroidism was the only dysfunction (18%) found in controls. Hyperthyroidism was associated with postmenopausal patients, as shown by significantly higher mean T3 and T4 values and lower TSH levels in this group of breast cancer patients than in controls. The majority of positive ERss tumors were clustered in the postmenopausal patients and all cases presenting subclinical hyperthyroidism in this subgroup concomitantly exhibited Erss-positive tumors. Subclinical hyperthyroidism was present in only one of 6 premenopausal patients. We show here that postmenopausal breast cancer patients have a significantly increased thyroid hormone/E2 ratio (P < 0.05), suggesting a possible tumor growth-promoting effect caused by this misbalance.