Second primary neoplasms following breast cancer in Saarland, Germany, 1968-1987

Risks of second non-breast primaries following breast cancer in women: a systematic review and meta-analysis

BACKGROUND

Second primary cancer incidence is rising among breast cancer survivors. We examined the risks of non-breast second primaries, in combination and at specific cancer sites, through a systematic review and meta-analysis.

METHODS

We conducted a systematic search of PubMed, Embase, and Web of Science, seeking studies published by March 2022. We included studies that reported standardized incidence ratios (SIRs), with associated standard errors, assessing the combined risk of second non-breast primaries following breast cancer. We performed meta-analyses of combined second primary risks, stratifying by age, follow-up duration, and geographic region. We also assessed second primary risks at several specific sites, stratifying by age. The inverse variance method with DerSimonian-Laird estimators was used in all meta-analyses, assuming a random-effects model. Associated biases and study quality were evaluated using the Newcastle-Ottawa scale.

RESULTS

One prospective and twenty-seven retrospective cohort studies were identified. SIRs for second non-breast primaries combined ranged from 0.84 to 1.84. The summary SIR estimate was 1.24 (95% CI 1.14-1.36, I2: 99%). This varied by age: the estimate was 1.59 (95% CI 1.36-1.85) when breast cancer was diagnosed before age 50, which was significantly higher than in women first diagnosed at 50 or over (SIR: 1.13, 95% CI 1.01-1.36, p for difference: < 0.001). SPC risks were also significantly higher when based on Asian, rather than European, registries (Asia-SIR: 1.47, 95% CI 1.29-1.67. Europe-SIR: 1.16, 95% CI 1.04-1.28). There were significantly increased risks of second thyroid (SIR: 1.89, 95% CI 1.49-2.38), corpus uteri (SIR: 1.84, 95% CI 1.53-2.23), ovary (SIR: 1.53, 95% CI 1.35-1.73), kidney (SIR: 1.43, 95% CI 1.17-1.73), oesophagus (SIR: 1.39, 95% CI 1.26-1.55), skin (melanoma) (SIR: 1.34, 95% CI 1.18-1.52), blood (leukaemia) (SIR: 1.30, 95% CI 1.17-1.45), lung (SIR: 1.25, 95% CI 1.03-1.51), stomach (SIR: 1.23, 95% CI 1.12-1.36) and bladder (SIR: 1.15, 95% CI 1.05-1.26) primaries.

CONCLUSIONS

Breast cancer survivors are at significantly increased risk of second primaries at many sites. Risks are higher for those diagnosed with breast cancer before age 50 and in Asian breast cancer survivors compared to European breast cancer survivors. This study is limited by a lack of data on potentially confounding variables. The conclusions may inform clinical management decisions following breast cancer, although specific clinical recommendations lie outside the scope of this review.

Risk of second primary cancer among breast cancer patients: A systematic review and meta-analysis

Objectives

The aim of this study was to estimate the extra risk of second primary cancer among breast cancer patients.

Methods and materials

This is a systematic review. A comprehensive search of literature was performed in PubMed, Web of Science, Cochrane library, and Scopus. The search included all published studies up to October 2022. This systematic review included studies published in the English language that reported the risk of second primary non-breast cancer [i.e., standardized incidence ratio (SIR)] among breast cancer patients older than 15 years. After evaluating the methodological quality of the selected studies, SIRs were pooled with consideration of heterogeneity among studies. The estimates were pooled by age and time since the diagnosis of primary breast cancer for both sexes (male and female). Age was categorized based on before 50 years and after 50 years, and time was categorized as duration of less than and more than 10 years, respectively.

Results

From 2,484 articles, 30 articles were eligible for inclusion in the systematic review and meta-analysis. The studies varied in terms of population, number of cases, study design, setting, and year of implementation of the research. The estimated SIR for men and women was 1.28 (95% CI: 1.18, 1.38) and 1.27 (95% CI: 1.15, 1.39), respectively. Women diagnosed with breast cancer before menopause [SIR: 1.52 (95% CI: 1.34, 1.71) vs. 1.21 (95% CI: 1.08, 1.34)] as well as women after 10 years since their breast cancer diagnosis [1.33 (95% CI: 1.22, 1.431) vs. 1.24 (95% CI: 1.10, 1.37)] were at a higher risk of developing second primary cancer. Among men, while there were no differences in risk based on age, with the increase of time, the risk of second primary cancer was reduced [SIR: 1.22 (95% CI: 1.12, 1.33) vs. 1.00 (95% CI: 0.79, 1.22)].

Conclusion

There is an extra risk of second primary cancer among breast cancer patients. The extra risk should be considered for further screening and preventive measures among this population.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=336062, identifier (CRD42022336062).

Contralateral breast cancer risk in patients with ductal carcinoma in situ and invasive breast cancer

We aimed to assess contralateral breast cancer (CBC) risk in patients with ductal carcinoma in situ (DCIS) compared with invasive breast cancer (BC). Women diagnosed with DCIS (N = 28,003) or stage I-III BC (N = 275,836) between 1989 and 2017 were identified from the nationwide Netherlands Cancer Registry. Cumulative incidences were estimated, accounting for competing risks, and hazard ratios (HRs) for metachronous invasive CBC. To evaluate effects of adjuvant systemic therapy and screening, separate analyses were performed for stage I BC without adjuvant systemic therapy and by mode of first BC detection. Multivariable models including clinico-pathological and treatment data were created to assess CBC risk prediction performance in DCIS patients. The 10-year cumulative incidence of invasive CBC was 4.8% for DCIS patients (CBC = 1334). Invasive CBC risk was higher in DCIS patients compared with invasive BC overall (HR = 1.10, 95% confidence interval (CI) = 1.04-1.17), and lower compared with stage I BC without adjuvant systemic therapy (HR = 0.87; 95% CI = 0.82-0.92). In patients diagnosed ≥2011, the HR for invasive CBC was 1.38 (95% CI = 1.35-1.68) after screen-detected DCIS compared with screen-detected invasive BC, and was 2.14 (95% CI = 1.46-3.13) when not screen-detected. The C-index was 0.52 (95% CI = 0.50-0.54) for invasive CBC prediction in DCIS patients. In conclusion, CBC risks are low overall. DCIS patients had a slightly higher risk of invasive CBC compared with invasive BC, likely explained by the risk-reducing effect of (neo)adjuvant systemic therapy among BC patients. For support of clinical decision making more information is needed to differentiate CBC risks among DCIS patients.

Association between breast cancer and the risk of colorectal cancer

BACKGROUND

The literature to date has suggested a potential increase in colorectal cancer (CRC) among patients with breast cancer.

METHODS

We performed a systematic review of the literature and included 37 retrospective cohort studies and 8 case-control studies. The primary aim was to determine the prevalence of CRC. Secondary aims included analysis of adenomatous polyps and analysis of CRC prevalence by age. We calculated pooled prevalence rates and odds ratios (ORs) using random effects models with 95% confidence intervals (CI).

RESULTS

We identified 1,055,917 individuals with breast cancer among whom 9097 cases of CRC were detected. The pooled event rate for CRC was 0.7% (95% CI, 0.6%-0.9%; I²=97%). Four case-control studies reported prevalence of CRC (N=17,873 patients with breast cancer and 70,366 controls), including 46 cases of CRC in the patients with breast cancer, and 272 CRC in the controls (OR, 1.2; 95% CI, 0.4%-3.7%; P = .7). Six studies reported prevalence of advanced adenomas in patients with breast cancer (N=1087) compared with controls (N=1356) with 62 cases of advanced adenomas in patients compared with 47 in the controls (OR, 1.5; 95% CI, 0.97-2.2; P = .07). In patients with breast cancer <50 years old (4 studies, N=64,706), the pooled OR was increased (OR, 2.5; 95% CI, 1.7-3.5; P =.001). In 3 studies of women <45 years old (N=92,594), the risk was increased (OR, 2.3; 95% CI, 1.7-2.6; P < .001).

CONCLUSIONS

Patients with breast cancer should not undergo CRC screening at intervals different from the general population. In patients with breast cancer <50 years old, CRC screening should be considered at age 45 years.

Gynecological Cancer as a Second Malignancy in Patients With Breast Cancer

Purpose

The aim of this study was to determine the incidence and risk factors for gynecological cancer as second malignancy (SM) after treatment of breast cancer (BC).

Methods and Materials

Between January 1985 and December 2007, a total of 2756 patients with BC were analyzed for gynecological cancers as an SM. Analysis was carried out for patient-, disease-, and treatment-related characteristics. The Cox proportional hazards regression model was used to estimate the relative risk of gynecologic malignancies.

Results

The median age at BC diagnosis was 49 years and median follow-up of 14 years. In total, 25 cases of gynecological cancer were noted with an incidence of 0.9%. We observed 9 ovarian and endometrium (0.3%) as well as 7 uterine cervix (0.25%) cancers. Family history of BC was the most significant risk factor for SM (relative risk, 7.4; 95% confidence interval, 3.03–18.28; P<0.001). Women with a family history of BC had a higher incidence of endometrial (12%) and ovarian (16%) cancer compared with those who have no family history (0.1%, P = 0.003). Statistically significant higher incidence of endometrial cancer was seen in patients undergoing hormonal therapy (0.4%) as compared with those who are not undergoing hormonal therapy (0.1%, P = 0.001). Most of the endometrial (88.9%) and cervical (71%) cancers were detected at an early stage but ovarian cancers (66.6%) in advanced stage. Chemotherapy and radiotherapy did not increase the risk of gynecological SM.

Conclusions

Women with BC are at risk of developing a second primary gynecological malignancy particularly of endometrium and ovary. Family history of BC was a high risk factor for gynecologic SM. These patients should be followed up for its early detection.

Increased incidence of thyroid cancer among breast cancer survivors: an analysis of the SEER-9 database (1973–2011)

Aims: We sought to re-examine the incidence of thyroid cancer among breast cancer survivors by performing a population-based, cohort analysis using the SEER-9 database. Methods: We identified 704,370 breast cancer patients, 49,663 thyroid cancer patients and 1526 patients who developed thyroid cancer after breast cancer (B1T). Results: Risk for developing thyroid cancer is greatest among survivors diagnosed with breast cancer at age less than 50 years. In general, B1T patients are younger with smaller tumors, and have a greater percentage of invasive ductal carcinoma. They develop thyroid cancer at an older age, and have a greater percentage of aggressive subtypes. Conclusion: Recognition of this association between thyroid and breast cancer should prompt increased awareness in these cancer patient populations.

Skin cancer risk in BRCA1/2 mutation carriers

Women with BRCA1/2 mutations have an elevated risk of breast and ovarian cancer. These patients and their clinicians are often concerned about their risk for other cancers, including skin cancer. Research evaluating the association between BRCA1/2 mutations and skin cancer is limited and has produced inconsistent results. Herein, we review the current literature on the risk of melanoma and nonmelanoma skin cancers in BRCA1/2 mutation carriers. No studies have shown a statistically significant risk of melanoma in BRCA1 families. BRCA2 mutations have been linked to melanoma in large breast and ovarian cancer families, though a statistically significant elevated risk was reported in only one study. Five additional studies have shown some association between BRCA2 mutations and melanoma, while four studies did not find any association. With respect to nonmelanoma skin cancers, studies have produced conflicting results. Given the current state of medical knowledge, there is insufficient evidence to warrant increased skin cancer surveillance of patients with a confirmed BRCA1/2 mutation or a family history of a BRCA1/2 mutation, in the absence of standard risk factors. Nonetheless, suspected BRCA1/2 mutation carriers should be counselled about skin cancer risks and may benefit from yearly full skin examinations.

Risk of second cancers cancer after a first primary breast cancer: a systematic review and meta-analysis

OBJECTIVE

To examine the scientific evidence and the risk of second primary cancers in women diagnosed with a first primary breast cancer.

METHODS

The literature was searched in Pubmed and Embase and included studies published up to June 2013, using population-based data and IARC/AICR codification rules for multiple primary cancers. A qualitative synthesis was carried out and the methodological quality of the studies evaluated. Standardised incidence ratios (SIRs) on second cancer risk, weighted by the standard error of each study, were pooled using fixed and random effects models. SIRs were also pooled by age at diagnosis (<50 and ≥ 50 years), and time since diagnosis of the first breast cancer (<10 and ≥ 10 years).

RESULTS

15 out of 710 articles fulfilled the inclusion criteria. All of them were retrospective cohort studies either population-based (13 studies) or hospital-based studies (2 studies). The studies varied with respect to number of cases, selection criteria, definition of multiple primary cancers, and the second cancer sites included. SIRs reported in these studies for all cancers combined varied from 1.0 to 1.4. The pooled SIR estimate for second cancer risk was 1.17 (95% CI: 1.10-1.25). By age groups, SIR estimates were 1.51 (95% CI: 1.35-1.70) for women younger than 50 years and 1.11 (95% CI: 1.02-1.21) for those who were older. Women with breast cancer are at risk of second cancers within the first 10 years after the first breast cancer diagnosis (SIR: 1.19; 95% CI: 1.06-1.33), and thereafter (SIR: 1.26; 95% CI: 1.05-1.52).

CONCLUSION

This higher risk of second cancers in women diagnosed with a first primary breast cancer with respect to the general population emphasises the importance of prevention and control policies aimed at reducing incidence of second cancers.

Risk of second primary cancer after breast cancer treatment

Technological advances in both diagnosis and treatment of breast cancer lead to early detection and better treatment management. Consequently, the population of long-term survivors is on the rise. The risk of developing second cancers among breast cancer survivors was shown to be higher than that for the general population. The aim of this work was to review the literature on the risk of second primary cancer (SPC) after breast irradiation. Pubmed search of population-based studies on SPC after breast irradiation was conducted and the findings (in terms of Standardised Incidence Ratio) were collated and discussed. Several studies confirmed the link between breast tumour irradiation and risk of SPC, showing a small, but valid risk. There are, however, confounding factors that can either underestimate or overestimate risks: misclassification of tumour status, genetic inheritance, smoking, environmental factors, and the lack of accurate data in cancer registries. While isolating these potential triggers might be difficult, this approach would allow better discernability between radiotherapy-related risks and those generated by other factors. It is also important to evaluate the current status of treatment-related late effects and to lower such risks by minimising the dose delivered to normal tissues.

Risk of second primary cancer among women with breast cancer: a population-based study in Granada (Spain)

OBJECTIVE

The higher risk of developing new cancers in breast cancer survivors is a public health concern. Our aim was to examine risk of second primary cancers among women diagnosed with breast cancer.

METHODS

We studied two cohorts of female cancer patients identified in a population-based cancer registry in Granada (Spain): women first diagnosed with a primary breast cancer (n=5897) and those with a primary cancer in another site (n=22,814), followed during 1985-2007 for second cancers and breast cancer occurrence, respectively. We used Standardized Incidence Ratios (SIRs) to estimate second cancer risk by age (<50y, ≥50y), time since diagnosis (≤5y, >5y) and calendar periods (≤1995, >1996). SIR for breast cancer was calculated in the second cohort.

RESULTS

The risk of developing second cancers (n=314) was 39% higher (95% CI=1.23-1.54) among breast cancer patients, and particularly high among women under 50 (SIR=1.96, 95% CI=1.48-2.44). Excess risk for endometrial cancer (SIR=3.04, 95% CI=2.14-3.94) was statistically significant and remained so in women over 50. Younger women were at higher risk of second ovarian cancer (SIR=4.90, 95% CI=1.27-8.53). Increased SIRs were observed during the first five years after breast cancer diagnosis, whereas SIRs decreased thereafter. Breast cancer incidence (n=171) was not higher among women previously diagnosed with other cancer types (SIR=0.86, 95% CI=0.74-1.00).

CONCLUSION

Women diagnosed with breast cancer have a higher incidence of second primary cancers, particularly of endometrial cancer in women over 50 at diagnosis, and ovarian cancer in younger women. These findings may be explained by treatment-related effects or shared risk factors.

[Follow-up in patients with early breast cancer]

Breast cancer incidence remains the highest among gynaecologic neoplasms. Once they have achieved their treatments, patients should undergo careful follow-up. It aims at detecting early local recurrence or controlateral breast cancer. Based on large cohorts, clinical and radiological follow-up procedures come from guidelines realised by scientific organisations. We evaluated our regional practices in Franche-Comté and compared them to current guidelines. Patients with early breast cancer positive for hormonal receptors filled a questionnaire concerning their follow-up. It included patients treated from 1999 to 2005. When frequency of consultation is evaluated, only half of the patients undergo what is recommended. Whereas mammography and non-validated complementary exams are more regularly realised. Patients consulting more one practician have a better compliance. Our study underlines significant disparities among patients follow-up. Better interactions between physicians and a greater implication of patients in their follow-up would increase its quality.

Relation of risk of contralateral breast cancer to the interval since the first primary tumour

BACKGROUND

There is no consensus on how to separate contralateral breast cancer (CBC) occurring as distant spread of the primary breast cancer (BC) from an independent CBC.

METHODS

We used standardised incidence ratios (SIRs) to analyse the variations in the risk of CBC over time among 6629 women with BC diagnosed between 1954 and 1983. To explore the most appropriate cutoff to separate the two types of CBC, we analysed the deviance between models including different cutoff points as compared with the basal model with no cutoff date. We also performed a prognostic study through a Cox model.

RESULTS

The SIR was much higher during the first 2 years of follow-up than afterwards. The best cutoff appeared to be 2 years. The risk of early CBC was linked to tumour spread and the risk of late CBC was linked to age and to the size of the tumour. Radiotherapy was not selected by the model either for early or late CBC risk.

CONCLUSION

A clearer pattern of CBC risk might appear if studies used a similar cutoff time after the initial BC.

[Synchronous sigmoid colon and breast cancers in man]

We report the case of 72-year-old man with sigmoid colon cancer associated with synchronous right breast cancer. However, in the present case, we found breast cancer insidiously at physical exam. The patient died after six months after the dissemination of the breast cancer.

Second malignancies after breast cancer: the impact of different treatment modalities

Treatment for non-metastatic breast cancer (BC) may be the cause of second malignancies in long-term survivors. Our aim was to investigate whether survivors present a higher risk of malignancy than the general population according to treatment received. We analysed data for 16 705 BC survivors treated at the Curie Institute (1981-1997) by either chemotherapy (various regimens), radiotherapy (high-energy photons from a 60Co unit or linear accelerator) and/or hormone therapy (2-5 years of tamoxifen). We calculated age-standardized incidence ratios (SIRs) for each malignancy, using data for the general French population from five regional registries. At a median follow-up 10.5 years, 709 patients had developed a second malignancy. The greatest increases in risk were for leukaemia (SIR: 2.07 (1.52-2.75)), ovarian cancer (SIR: 1.6 (1.27-2.04)) and gynaecological (cervical/endometrial) cancer (SIR: 1.6 (1.34-1.89); P<0.0001). The SIR for gastrointestinal cancer, the most common malignancy, was 0.82 (0.70-0.95; P<0.007). The increase in leukaemia was most strongly related to chemotherapy and that in gynaecological cancers to hormone therapy. Radiotherapy alone also had a significant, although lesser, effect on leukaemia and gynaecological cancer incidence. The increased risk of sarcomas and lung cancer was attributed to radiotherapy. No increased risk was observed for malignant melanoma, lymphoma, genitourinary, thyroid or head and neck cancer. There is a significantly increased risk of several kinds of second malignancy in women treated for BC, compared with the general population. This increase may be related to adjuvant treatment in some cases. However, the absolute risk is small.

The impact of adjuvant therapy on contralateral breast cancer risk and the prognostic significance of contralateral breast cancer: a population based study in the Netherlands

Background The impact of age and adjuvant therapy on contralateral breast cancer (CBC) risk and prognostic significance of CBC were evaluated. Patients and Methods In 45,229 surgically treated stage I–IIIA patients diagnosed in the Netherlands between 1989 and 2002 CBC risk was quantified using standardised incidence ratios (SIRs), cumulative incidence and Cox regression analysis, adjusted for competing risks. Results Median follow-up was 5.8 years, in which 624 CBC occurred <6 months after the index cancer (synchronous) and 1,477 thereafter (metachronous). Older age and lobular histology were associated with increased synchronous CBC risk. Standardised incidence ratio (SIR) of CBC was 2.5 (95% confidence interval (95% CI) 2.4–2.7). The SIR of metachronous CBC decreased with index cancer age, from 11.4 (95% CI 8.6–14.8) when <35 to 1.5 (95% CI 1.4–1.7) for ≥60 years. The absolute excess risk of metachronous CBC was 26.8/10,000 person-years. The cumulative incidence increased with 0.4% per year, reaching 5.9% after 15 years. Adjuvant hormonal (Hazard rate ratio (HR) 0.58; 95% CI 0.48–0.69) and chemotherapy (HR 0.73; 95% CI 0.60–0.90) were associated with a markedly decreased CBC risk. A metachronous CBC worsened survival (HR 1.44; 95% CI 1.33–1.56). Conclusion Young breast cancer patients experience high synchronous and metachronous CBC risk. Adjuvant hormonal or chemotherapy considerably reduced the risk of CBC. CBC occurrence adversely affects prognosis, emphasizing the necessity of long-term surveillance directed at early CBC-detection.

Primary gynecological neoplasms and clinical outcomes in patients diagnosed with breast carcinoma

The purpose of this study was to quantify and describe nonmammary neoplasms (n-MN), particularly gynecological neoplasms, in a patient population previously diagnosed with breast cancer. Data were collected prospectively in our institutional review board-approved registry for patients diagnosed with infiltrating breast cancer or ductal carcinoma in situ. Patients who developed a second, n-MN were identified; neoplastic site, time to development after breast cancer, and clinical outcomes were recorded. FIGO stage was recorded for patients who developed a gynecological neoplasm. Synchronous bilateral breast cancer was defined as a second, contralateral diagnosis made within 12 months of the first and, similarly, synchronous n-MN were defined as those identified within 1 year of a breast cancer diagnosis. Outcome curves were generated using the method of Kaplan and Meier, and compared using the log-rank test. Of 4126 patients diagnosed with breast cancer, 3% developed a n-MN, the majority of which were nongynecological and asynchronous to the initial breast cancer diagnosis. Three percent of patients diagnosed with breast cancer were diagnosed with a second, n-MN. Among patients who developed a n-MN, most developed a nongynecological cancer more than 1 year after the initial breast cancer diagnosis, and their outcomes were significantly worse than those patients who did not develop a n-MN.

Risk of second cancer among women with breast cancer

A large number of women survive a diagnosis of breast cancer. Knowledge of their risk of developing a new primary cancer is important not only in relation to potential side effects of their cancer treatment, but also in relation to the possibility of shared etiology with other types of cancer. A cohort of 525,527 women with primary breast cancer was identified from 13 population-based cancer registries in Europe, Canada, Australia and Singapore, and followed for second primary cancers within the period 1943-2000. We used cancer incidence rates of first primary cancer for the calculation of standardized incidence ratios (SIRs) of second primary cancer. Risk of second primary breast cancer after various types of nonbreast cancer was also computed. For all second cancer sites combined, except contralateral breast cancer, we found a SIR of 1.25 (95% CI = 1.24-1.26) on the basis of 31,399 observed cases after first primary breast cancer. The overall risk increased with increasing time since breast cancer diagnosis and decreased by increasing age at breast cancer diagnosis. There were significant excesses of many different cancer sites; among these the excess was larger than 150 cases for stomach (SIR = 1.35), colorectal (SIR = 1.22), lung (SIR = 1.24), soft tissue sarcoma (SIR = 2.25), melanoma (SIR = 1.29), non-melanoma skin (SIR = 1.58), endometrium (SIR = 1.52), ovary (SIR = 1.48), kidney (SIR = 1.27), thyroid gland (SIR = 1.62) and leukaemia (SIR = 1.52). The excess of cancer after a breast cancer diagnosis is likely to be explained by treatment for breast cancer and by shared genetic or environmental risk factors, although the general excess of cancer suggests that there may be additional explanations such as increased surveillance and general cancer susceptibility.

Risks of second primary breast and urogenital cancer following female breast cancer in the south of The Netherlands, 1972–2001

A cohort of 9919 breast cancer patients from the population-based Eindhoven Cancer Registry was followed for vital status and development of second cancer. Person-year analysis was applied to determine the risk of second primary breast or urogenital cancer among breast cancer patients and to assess its correlation with age, treatment and time since the first breast cancer diagnosis. Women with previous breast cancer have an elevated risk of overall second breast or urogenital cancer. The largest relative risk was observed for second breast cancer (SIR (standardised incidence ratio) 3.5; 95% confidence interval (CI) 3.2-3.8) and second ovarian cancer (SIR 1.7; 95% CI 1.2-2.3). The absolute excess risk was highest for second breast cancer (64/10,000 patients/year). However, breast cancer has an inverse relationship to risk of cervical cancer. Changes in behavioural risk factors are important for lowering the risk of second cancer after breast cancer.

A descriptive study of second primary malignancies associated to breast cancer in a mexican Hispanic population

Breast cancer is the second most frequent tumor in Mexico. Patients diagnosed with this cancer have a higher risk of developing a second malignancy. The objective of our study was to see the frequency, types of second cancers, and its impact on survival, in order to be able to deliver a proper and efficient follow up to these patients, because our patients differ from the population of breast cancer in the rest of the world. Our patients are younger and therefore at higher risk. The clinical records of breast cancer patients treated at the Instituto Nacional de Cancerologia Mexico from 1983 to 1992 were reviewed. In 1370 evaluable patients, 77 (5.6%) developed a second neoplasm, of those, 56 (72.7%) in the contralateral breast and 21 in other sites (27.3%), thyroid was the most frequent followed by ovary and endometrium. Mean age of the patients was 51.5 yr, 45.5 for the other breast and 55.5 for other malignancies (p = 0.01). Median survival for all the group was of 180 mo (3-238). Patients were significantly younger in the contralateral breast group, although all our breast cancer patients are younger. The most frequent second malignancy after the other breast, was thyroid followed by ovary and endometrium with similar survival for both groups.

Primary Malignancy after Primary Female Breast Cancer in the South of the Netherlands, 1972–2001

OBJECTIVES

To assess the risk of second primary cancers among women with previous breast cancer and calculate the excess burden of second cancer in the population.

METHODS

A population-based longitudinal study was conducted using the Eindhoven cancer registry data on 9919 breast cancer patients diagnosed in the period 1972-2000 and followed until 2001. Standardised incidence ratios (SIR) and absolute excess risks (AER) were calculated.

RESULTS

In total, 1298 (13%) women developed a second primary cancer. The risk of overall second cancer was higher among breast cancer patients compared to the general population (SIR: 2.8; 95% CI: 2.6-2.9), with an AER of 115 second cancers for every 10,000 breast cancer patients per year. High SIR and AER were observed for breast cancer (SIR: 4.1; 95% CI: 3.8-4.4; AER: 64/10,000 patients/year) and ovarian cancer (SIR: 2.0; 95% CI: 1.5-2.7; AER: 4.5/10,000 patients/year).

CONCLUSIONS

Our recent data show that women with previous breast cancer have an elevated risk of developing a second cancer compared to the general population. Excess burden for the population is especially high for second cancers of the breast, ovary and colon. Screening may only be justified for breast, ovary and colon cancer in certain groups of patients.

Association between female breast cancer and cutaneous melanoma

Epidemiologic studies have provided suggestive evidence of a link between cutaneous melanoma (CM) and breast cancer (BC). Moreover, carriers of mutations in the breast cancer predisposition gene, BRCA2, have an increased risk of melanoma while carriers of mutations in the melanoma susceptibility gene, CDKN2A, exhibit a higher than expected risk of breast cancer. These findings raise the possibility that pathways involved in the development of CM and BC overlap and that survivors of one cancer may be prone to develop the other. To this end, we set out to determine if survivors of female BC in the Surveillance, Epidemiology and End Result (SEER) database are at increased risk for CM and vice versa. We followed female BC patients registered in the 1973-1999 SEER database for development of a second CM and female CM patients for the development of a second BC. The expected number of cases was then compared to the observed number of cases using standardized incidence ratios. Overall, we found a modest but statistically significant increased risk of CM among female BC survivors and vice versa. Among young BC patients, we observed a 46% elevated risk of a second CM. Women who underwent radiation therapy exhibited a 42% increased risk for CM. The risks of BC among female CM survivors and CM among BC survivors were also elevated, albeit to a much lesser degree (overall, 11% and 16%, respectively). We found a mutual association between female BC and CM. The elevated risk for CM, especially among younger BC patients, suggests that the genetic observations from high-risk groups may also be operative at a much lower level in the general BC population.

The Descriptive Epidemiology of Second Primary Breast Cancer

BACKGROUND

It is well established that the incidence rates of first primary breast cancer have been increasing over time. In contrast, the incidence rates of second primary breast cancer are largely undocumented. This study describes the epidemiology of second primary breast cancer among a population-based cohort of 305,533 U.S. women diagnosed with breast cancer between 1973 and 1998.

METHODS

We compared age-specific incidence rates for overall and second primary breast cancer according to year of diagnosis and demographic and tumor characteristics.

RESULTS

Overall, age-specific rates of breast cancer increased with increasing age and year of diagnosis, whereas incidence of second primary breast cancer peaked among young women and declined after 1988. Consistent with what is known about genetic susceptibility to breast cancer, at every age the rate of second primaries was greater than the overall rate; among women age 20 to 29 years the rate of second primary was more than 100 times greater. Although overall age-specific rates of breast cancer for African-American women were lower than for whites, rates of second primaries were higher. Women with a first primary that was either lobular or medullary had a greater likelihood of developing a second primary, although, there were relatively few with these histologic types.

CONCLUSIONS

The pattern of incidence rates for first and second primary breast cancer differ markedly over time and by age.

Epidemiologic and molecular risk factors for contralateral breast cancer among young women

Women diagnosed with a first breast cancer before the age of 45 years have a greater than 5.0-fold risk of developing a second primary contralateral breast cancer (CBC) than women in the general population have of developing a first breast cancer. Identifying epidemiologic or molecular factors that influence CBC risk could aid in the development of new strategies for the management of these patients. A total of 1285 participants in two case-control studies conducted in Seattle, Washington, who were 21-44 years of age when diagnosed with a first invasive breast carcinoma from 1983 to 1992, were followed through December 2001. Of them, 77 were diagnosed with CBC and 907 tumour tissues from first cancers were analysed. Women with body mass indices (BMIs) >/=30 kg m(-2) had a 2.6-fold greater risk (95% CI: 1.1-5.9) of CBC compared to women with BMIs </=19.9 kg m(-2). Women whose first tumour was c-erbB-2 positive had a 1.7-fold (95% CI: 1.0-3.0) excess CBC risk. Body mass index and c-erbB-2 expression may be risk factors for CBC in young women. Further observational studies are needed to confirm these findings and to evaluate whether testing for c-erbB-2 in this population may help identify those at high risk for CBC.

Risk factors for colorectal cancer following breast cancer

OBJECTIVE

To investigate risk factors for colorectal cancer following breast cancer.

METHODS

In this nested case-control study, all women (n = 14,900) with a first primary breast cancer (1978-1992) were identified from the western Washington population-based Surveillance, Epidemiology, and End Results Cancer Registry. Cases (n = 160) developed a second primary colorectal cancer before 1995, at least 6 months after the first cancer diagnosis. Controls (n = 310, matched to the cases on calendar year, age and breast cancer stage) were randomly selected from those who did not develop a second primary cancer and who survived to the case's colorectal cancer diagnosis date. Characteristics of the cases and controls at initial diagnosis were compared using conditional logistic regression.

RESULTS

The incidence of colorectal cancer was associated with a family history of breast cancer (v.s. no family history, matched odds ratio (mOR) = 2.1, 95% confidence interval (CI): 1.1-4.1), high body mass index (> or = 30kg/m2 v.s. < 30kg/m2, mOR = 2.2, CI: 1.2-3.9), and lobular breast cancer histology (v.s. ductal, mOR = 2.0, CI: 0.9-4.4). Risk was unrelated to menopausal status, prior hormone replacement therapy and estrogen/progesterone receptor status of the breast tumors.

CONCLUSIONS

The risk of developing a second primary colorectal cancer may be elevated among certain subsets of breast cancer patients.

Cancer risk in women with previous breast cancer

BACKGROUND

Excess risks of several second neoplasms following breast cancer have been reported. However, these risks have still to be quantified.

PATIENTS AND METHODS

We considered 9,729 breast cancer patients registered by the Swiss Cancer Registries of Vaud and Neuchâtel (covering about 786,000 inhabitants) and followed up from 1974 to 1998.

RESULTS

Overall, 443 second primary neoplasms (other than second primary breast cancers) were observed versus 389 expected [standardised incidence ratio (SIR): 1.14; 95% confidence interval (CI) 1.04-1.25]. The SIRs were above unity for endometrium (SIR = 1.5), ovary (1.3), colorectum (1.1), gallbladder (1.4), cutaneous malignant melanoma (1.4), kidney (1.4), lymphomas (1.4) and leukaemias (1.2), as well as for selected tobacco-related neoplasms. The largest excess risk was found for soft tissue sarcomas (STS) with 10 cases observed versus 3.1 expected (SIR = 3.2; 95% CI 1.5-5.9). Of these, eight occurred in potentially irradiated areas.

CONCLUSIONS

This analysis confirms the existence of a modest excess in several neoplasms occurring after breast cancer. The substantial excess of STS confirms the strong association between irradiation and STS.

Risk of ovarian cancer in breast-cancer patients with a family history of breast or ovarian cancer: a population-based cohort study

BACKGROUND

Patients with breast cancer who have mutations in the high penetrance genes BRCA1 and BRCA2, have an increased risk of ovarian cancer. Because these mutations are rare, easily obtained information such as age and family history of breast or ovarian cancer might be preferable for assessment of ovarian cancer risk in clinical practice.

METHODS

We linked data from the Swedish Cancer Register to the Swedish Generation Register and generated a cohort of 30552 breast-cancer patients born after 1931, with information on breast and ovarian cancer diagnosis from 146117 first-degree relatives. Standardised incidence ratios (SIRs) with 95% CIs were calculated with nationwide rates of ovarian cancer, adjusted for age and calendar year.

FINDINGS

During a mean follow-up of 6 years, 122 incident ovarian cancers were identified in the cohort, yielding an overall SIR of 2.0 (95% CI 1.6-2.4). The risk was higher in breast-cancer patients diagnosed before the age of 40 years, with a family history of breast cancer (5.6; 1.8-13.1) or ovarian cancer (17.0; 3.5-50.0). A consistently increased risk was noted in patients with a relative who was diagnosed before the age of 50 years, with either breast or ovarian cancer. Women with a family history of ovarian cancer have an almost 10% risk of developing ovarian cancer before the age of 70.

INTERPRETATION

In young women with breast cancer, the risk of ovarian cancer is greatly raised when a family history of breast or ovarian cancer is present. Close medical surveillance, and perhaps even prophylactic oophorectomy, might be justified in high-risk groups.

Breast cancer risk in women with a primary ovarian cancer--a case-control study

Register-based studies show that women with ovarian cancer are at increased risk of developing breast cancer. Primary suggested explanations are heredity factors and a common hormonal aetiology. However, clinical surveillance that is provided for cancer patients during, and after, treatment of their primary malignancies together with possible mistakes in the registering procedures could affect the risk estimates. In order to examine these factors in women registered with ovarian cancer who develop subsequent breast cancer, a case-control study was performed. Using a regional Swedish cancer registry including 5060 women registered with ovarian cancer, 89 cases of breast cancer were found. After corrections for discrepancies in the registered and recorded information, 75 cases remained, of which 72 cases were included in the study. Information concerning possible risk factors were extracted from hospital records and compared with 177 matched controls. Suggested risk factors such as parity (relative risk (RR)=1.41), late age at menopause (52-61 years; RR=1.61) and heredity for breast and/or ovarian cancer (RR=1.50) were all connected with a non-significant increased risk of subsequent breast cancer. In all, 43% of the breast cancer cases were revealed without preceding symptoms at clinical follow-up, indicating that increased clinical surveillance is a factor of importance when explaining the increased risk. The fact that only 75 (missing records included) out of the 89 registered breast cancer cases could be linked to the preceding ovarian cancer indicates that the actual risk of developing breast cancer is smaller than previously described. The clinical implications from these findings could be that, beside general screening programmes and health controls offered to women in cancer-prone families, additional mammography examinations based on the assumption of an increased risk of breast cancer are not warranted in ovarian cancer patients.

Incidence of second primary breast cancer among women with a first primary in Manitoba, Canada

Second primary breast cancer is of importance because of the increasing incidence of first primary breast cancer and improved survival. There is lack of information on the disease in Canada. We studied 14,220 women with a first primary breast cancer (invasive only) diagnosed during the period from 1970 to 1997, in Manitoba, Canada. A breast cancer was considered to be a second primary if it was an invasive lesion diagnosed at least six months after the diagnosis of an initial primary breast cancer. The incidence rate of second primary breast cancer was approximately six per 1,000 person-years, and the cumulative incidence during the 28-year study period was 14.3%. Average age at diagnosis of first primary breast cancer had increased significantly since 1970. The incidence was higher in 1975-1979, and there was no significant difference among other study periods after adjustment for the age at diagnosis of first primary breast cancer. Standardized incidence ratios showed no significant difference among six age groups after adjusting for calendar year. However, women with a first primary breast cancer had an increased risk of developing a second primary breast cancer compared with the risk of developing a first primary breast cancer among the general female population. The SIR was markedly greater among women who had a first primary breast cancer before the age of 40 years, and decreased significantly with increasing age at diagnosis of first primary breast cancer. The data provide epidemiological information on second primary breast cancer risk for the general female population in Manitoba, Canada.

Second primary cancers following breast cancer in the Japanese female population

To assess the risk of developing second primary cancers following breast cancer in Japanese females, we performed a retrospective cohort study of 2786 patients who were newly diagnosed with breast cancer at our hospital between 1970 - 1994, until the end of 1995 (average follow-up period, 8.6 years). The expected number of each second primary cancer was calculated by multiplying the number of appropriate person-years at risk by the corresponding age- and calendar period-specific cancer incidence rates for women obtained from the Osaka Cancer Registry. One hundred and seventeen patients developed a second primary cancer other than subsequent breast cancer, yielding an observed-to-expected ratio (O / E) of 1.3 [95% confidence interval (CI) = 1.1 - 1.6]. The risk for developing a second primary cancer was significantly elevated during the first year following the diagnosis of breast cancer, and decreased with the passage of time to unity. A significantly increased risk was noted for the development of ovarian cancer (O / E = 2.4, 95% CI = 1.0 - 4.6), thyroid cancer (O / E = 3.7, 95% CI = 1.5 - 7.6) and non-Hodgkin's lymphoma (NHL) (O / E = 3.5, 95% CI = 1.4 - 7.1) among the breast cancer patients compared with the general population. Patients who received hormonal therapy as the breast cancer treatment showed a significantly increased risk for ovarian cancer (O / E = 5.5, 95% CI = 1.8 - 12.9). Patients who received chemotherapy as the breast cancer treatment had an increased risk for NHL (O / E = 5.0, 95% CI = 1.6 - 11.6). These findings indicate that Japanese female patients with breast cancer had a 30% higher risk of developing a second primary cancer than the general population, the higher risk being manifested in the early period following the diagnosis of breast cancer. Medical surveillance of breast cancer patients for NHL, as well as for ovarian cancer and thyroid cancer, is required.

Increased risk of second cancers following breast cancer: role of the initial treatment

OBJECTIVES AND METHODS

The risk of second primary malignancies (SMN) was studied in a cohort of 4,416 one-year survivors of a breast cancer. The role of the menopausal status and of the initial treatment modalities (surgery, radiotherapy, and chemotherapy) was investigated.

RESULTS

Excluding second primary breast cancer and non-melanoma skin cancer, a total of 193 (4.4%) patients developed a SMN between 1973 and 1992, compared with 136 expected (Standardised Incidence Ratio, SIR = 1.4, 95% CI (1.2-1.6)). No trend towards either an increase or a decrease was noted in the SIR with time after treatment (p = 0.2). The greatest increase in the relative risk concerned soft tissue cancers (SIR = 13.0, 95% CI: 6.8-22.3), followed by leukaemia (SIR = 3.1, 95% CI: 1.7-5.0), melanoma (SIR = 2.7, 95% CI: 1.4-4.8), kidney (SIR = 2.5, 95% CI: 1.2-4.5), ovary (SIR = 2.0, 95% CI: 1.2-3.1) and uterine tumours (SIR = 1.9, 95% CI: 1.4-2.5). The SIR was 3.0 (95% CI 1.8-4.7) in women under 40 at the time of the breast cancer, 1.9 (95% CI: 1.4-2.4) in those aged 40-49 and 1.2 (95% CI 1.0-1.4) in those aged 50 or more. In the 2,514 women who had received radiotherapy as initial treatment without chemotherapy, the SIR for all SMN was 1.6 (95% CI: 1.1-2.3) fold higher than in those who had not received radiotherapy as initial treatment.

CONCLUSION

In conclusion, this study confirms the increased risk of second malignancies in women treated for a breast cancer, and particularly in those who were younger at the time of treatment for breast cancer. Our results also suggest that radiotherapy may play a role in the onset of these second lesions.

Cytological and immunocytochemical evaluation of thyroid and breast masses in patients with a previous neoplasm: case reports

The diagnosis of secondary tumours represents one of the most important fields in the application of fine needle aspiration cytology (FNAC). We studied two patients, one with a history of breast cancer and one with a previous tumour of the thyroid, who showed a second mass, in the thyroid and in the breast, respectively, during follow up. The aim of our study was to evaluate if cytology, performed on FNAC smears, may distinguish a metastatic lesion from a second primary tumour, or if further immunocytochemistry should be performed. Our data demonstrate that, while cytology may be indicative of a second primary tumour, the histotype should be confirmed by immunocytochemical staining.

Incidence of second primary cancers in three Italian population-based cancer registries

This is the first population-based study carried out in a southern European region to evaluate the risk of a cohort of cancer patients for developing further cancers. The Tuscany Tumour Registry, the Ragusa Cancer Registry and the Cancer Registry of Romagna, three of the 14 population-based cancer registries active in Italy, were involved in the present study. Overall, 19,252 incident cases of cancer of the female breast, and of the colon, rectum, lung and stomach were followed-up for 48 358.3 person-years. Only second metachronous cancers were considered. Controlateral breast cancers were analysed separately. Multiple primaries (MPs) were defined according to the IACR-IACR rules. The observed (O) numbers of MPs were compared with those expected (E) from age-, sex- and registry-specific incidence rates. Overall, 463 MPs were diagnosed (O/E = 0.87, P < 0.001). The O/E ratios for cancers of the colon (O/E = 0.66), rectum (O/E = 0.72) and all sites combined (O/E = 0.78) in males were significantly lower than expected. The deficit of observed MPs was significant during the first period (2-12 months) and increased over time. Patients over 65 years of age had a significant lower risk of MP, whereas young cancer patients had significantly higher risks for all cancers and for female breast cancer. Male lung cancer patients had a significantly reduced O/E ratio for stomach cancer (O/E = 0.21). Rectal cancer patients had reduced risks of developing stomach cancer and tumours of all sites combined and a 3-fold increased risk of kidney cancers. Colon cancer patients had an overall reduction in risk of MPs, but female colon cancer patients had a significantly increased risk for tumours of the ovary and small intestine; no significant results were found for primary stomach cancers. Female breast cancer patients had a significantly increased risk of rectal cancer (O/E = 1.97), and when synchronous and bilateral breast cancers were considered, significant overall increases in risk were seen for all cancer sites (O/E = 1.6) and for rectal (O/E = 2), and especially for breast cancers (O/E = 3). The cohort analysed had a lower risk of developing further independent tumours than the general population. Several artefacts may have biased these results: the exclusion of synchronous cancers greatly reduced the overall MP risk, and the age-related differences may have been due to reduced medical surveillance and diagnostic aggressiveness. We have confirmed the increased risk for kidney cancers in rectal cancer patients and the association between cancers of the colon and ovary. The significantly increased risk for rectal cancer in female breast cancer patients is probably due to hormonal and dietary factors. For female breast cancer patients, controlateral breast cancer represented the highest risk. The increased risk of cancer of the small intestine in patients with colon cancer may be due to overdiagnosis within increased medical surveillance.