Risk of second malignancies after adjuvant radiotherapy for breast cancer: a large-scale, single-institution review

Incident malignancies among older long-term breast cancer survivors and an age-matched and site-matched nonbreast cancer comparison group over 10 years of follow-up

BACKGROUND

Of the approximately 2.4 million American women with a history of breast cancer, 43% are aged ≥ 65 years and are at risk for developing subsequent malignancies.

METHODS

Women from 6 geographically diverse sites included 5-year breast cancer survivors (N = 1361) who were diagnosed between 1990 and 1994 at age ≥ 65 years with stage I or II disease and a comparison group of women without breast cancer (N = 1361). Women in the comparison group were age-matched and site-matched to breast cancer survivors on the date of breast cancer diagnosis. Follow-up began 5 years after the index date (survivor diagnosis date or comparison enrollment date) until death, disenrollment, or through 15 years after the index date. Data were collected from medical records and electronic sources (cancer registry, administrative, clinical, National Death Index). Analyses included descriptive statistics, crude incidence rates, and Cox proportional hazards regression models for estimating the risk of incident malignancy and were adjusted for death as a competing risk.

RESULTS

Survivors and women in the comparison group were similar: >82% were white, 55% had a Charlson Comorbidity Index of 0, and ≥ 73% had a body mass index ≤ 30 kg/m(2) . Of all 306 women (N = 160 in the survivor group, N = 146 in the comparison group) who developed a first incident malignancy during follow-up, the mean time to malignancy was similar (4.37 ± 2.81 years vs 4.03 ± 2.76 years, respectively; P = .28), whereas unadjusted incidence rates were slightly higher in survivors (1882 vs 1620 per 100,000 person years). The adjusted hazard of developing a first incident malignancy was slightly elevated in survivors in relation to women in the comparison group, but it was not statistically significant (hazard ratio, 1.17; 95% confidence interval, 0.94-1.47).

CONCLUSIONS

Older women who survived 5 years after an early stage breast cancer diagnosis were not at an elevated risk for developing subsequent incident malignancies up to 15 years after their breast cancer diagnosis.

Radiation therapy after breast-conserving surgery

SUMMARY Whole-breast irradiation in combination with breast-conserving surgery is a recognized standard alternative to mastectomy for the local treatment of early breast cancer. This article will review the evidence on the relationship of local control in the treated breast and survival, the indications of a boost dose to the tumor bed and the need for breast irradiation in ductal carcinoma in situ. Novel, shorter fractionation schemes allow the constraints of daily treatment courses over several weeks to be reduced, and recent technical improvements in treatment delivery will improve the results of treatment – in terms of local control and reduction of toxicity, and long-term sequelae. Research should focus on identifying molecular markers of radiation sensitivity and designing specific, targeted modulators of the radiation response in breast cancer.

Two cases of post-radiation sarcoma after breast cancer treatment

We describe two cases of post-radiation sarcoma after breast cancer treatment. The first patient was a 61-year-old woman who underwent partial mastectomy of the right breast and adjuvant whole breast irradiation 7 years previously. Subsequently, a rapidly growing mass from the anterior arc of the right fifth rib was incidentally detected on an abdomino-pelvic computed tomography scan. The second patient was a 70-year-old woman who received neoadjuvant chemotherapy and a partial mastectomy of the left breast 9 years ago. Adjuvant irradiation was delivered to the whole breast and supraclavicular region. Subsequently, an approximate 8 cm mass developed in the left axillary area. Both patients received wide excision of the tumor with negative resection margins. The pathological diagnoses were osteosarcoma and undifferentiated pleomorphic sarcoma, respectively. Although post-radiation sarcomas are rare complications with a poor prognosis, enhanced awareness and early detection by clinicians are essential to improve outcomes via curative surgical resection.

Second malignant neoplasms: assessment and strategies for risk reduction

Improvements in early detection, supportive care, and treatment have resulted in an increasing number of cancer survivors, with a current 5-year relative survival rate for all cancers combined of approximately 66.1%. For some patients, these survival advances have been offset by the long-term late effects of cancer and its treatment, with second malignant neoplasms (SMNs) comprising one of the most potentially life-threatening sequelae. The number of patients with SMNs is growing, with new SMNs now representing about one in six of all cancers reported to the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. SMNs reflect not only the late effects of therapy but also the influence of shared etiologic factors (in particular, tobacco and excessive alcohol intake), genetic susceptibility, environmental exposures, host effects, and combinations of factors, including gene-environment interactions. For selected SMNs, risk is also modified by age at exposure and attained age. SMNs can be categorized into three major groups according to the predominant etiologic factor(s): (1) treatment-related, (2) syndromic, and (3) those due to shared etiologic exposures, although the nonexclusivity of these groups should be underscored. Here we provide an overview of SMNs in survivors of adult-onset cancer, summarizing the current, albeit limited, clinical evidence with regard to screening and prevention, with a focus on the provision of guidance for health care providers. The growing number of patients with second (and higher-order) cancers mandates that we also further probe etiologic influences and genetic variants that heighten risk, and that we better define high-risk groups for targeted preventive and interventional clinical strategies.

Predicting the risk of secondary lung malignancies associated with whole-breast radiation therapy

PURPOSE

The risk of secondary lung malignancy (SLM) is a significant concern for women treated with whole-breast radiation therapy after breast-conserving surgery for early-stage breast cancer. In this study, a biologically based secondary malignancy model was used to quantify the risk of secondary lung malignancies (SLMs) associated with several common methods of delivering whole-breast radiation therapy (RT).

METHODS AND MATERIALS

Both supine and prone computed tomography simulations of 15 women with early breast cancer were used to generate standard fractionated and hypofractionated whole-breast RT treatment plans for each patient. Dose-volume histograms (DVHs) of the ipsilateral breast and lung were calculated for each patient on each plan. A model of spontaneous and radiation-induced carcinogenesis was used to determine the relative risks of SLMs for the different treatment techniques.

RESULTS

A higher risk of SLMs was predicted for supine breast irradiation when compared with prone breast irradiation for both the standard fractionation and hypofractionation schedules (relative risk [RR] = 2.59, 95% confidence interval (CI) = 2.30-2.88, and RR = 2.68, 95% CI = 2.39-2.98, respectively). No difference in risk of SLMs was noted between standard fractionation and hypofractionation schedules in either the supine position (RR = 1.05, 95% CI = 0.97-1.14) or the prone position (RR = 1.01, 95% CI = 0.88-1.15).

CONCLUSIONS

Compared with supine whole-breast irradiation, prone breast irradiation is associated with a significantly lower predicted risk of secondary lung malignancy. In this modeling study, fractionation schedule did not have an impact on the risk of SLMs in women treated with whole-breast RT for early breast cancer.

Quantification of contralateral breast dose and risk estimate of radiation-induced contralateral breast cancer among young women using tangential fields and different modes of breathing

PURPOSE

Whole breast irradiation with deep-inspiration breath-hold (DIBH) technique among left-sided breast cancer patients significantly reduces cardiac irradiation; however, a potential disadvantage is increased incidental irradiation of the contralateral breast.

METHODS AND MATERIALS

Contralateral breast dose (CBD) was calculated by comparing 400 treatment plans of 200 left-sided breast cancer patients whose tangential fields had been planned on gated and nongated CT data sets. Various anatomic and field parameters were analyzed for their impact on CBD. For a subgroup of patients (aged ≤45 years) second cancer risk in the contralateral breast (CB) was modeled by applying the linear quadratic model, compound models, and compound models considering dose-volume information (DVH).

RESULTS

The mean CBD was significantly higher in DIBH with 0.69 Gy compared with 0.65 Gy in normal breathing (P=.01). The greatest impact on CBD was due to a shift of the inner field margin toward the CB in DIBH (mean 0.4 cm; range, 0-2), followed by field size in magnitude. Calculation with different risk models for CBC revealed values of excess relative risk/Gy ranging from 0.48-0.65 vs 0.46-0.61 for DIBH vs normal breathing, respectively.

CONCLUSION

Contralateral breast dose, although within a low dose range, was mildly but significantly increased in 200 treatment plans generated under gated conditions, predominately due to a shift in the medial field margin. Risk modeling for CBC among women aged ≤45 years also pointed to a higher risk when comparing DIBH with normal breathing. This risk, however, was substantially lower in the model considering DVH information. We think that clinical decisions should not be affected by this small increase in CBD with DIBH because DIBH is effective in reducing the dose to the heart in all patients.

Second malignant neoplasms and cardiovascular disease following radiotherapy

Second malignant neoplasms (SMNs) and cardiovascular disease (CVD) are among the most serious and life-threatening late adverse effects experienced by the growing number of cancer survivors worldwide and are due in part to radiotherapy. The National Council on Radiation Protection and Measurements (NCRP) convened an expert scientific committee to critically and comprehensively review associations between radiotherapy and SMNs and CVD, taking into account radiobiology; genomics; treatment (ie, radiotherapy with or without chemotherapy and other therapies); type of radiation; and quantitative considerations (ie, dose-response relationships). Major conclusions of the NCRP include: 1) the relevance of older technologies for current risk assessment when organ-specific absorbed dose and the appropriate relative biological effectiveness are taken into account and 2) the identification of critical research needs with regard to newer radiation modalities, dose-response relationships, and genetic susceptibility. Recommendation for research priorities and infrastructural requirements include 1) long-term large-scale follow-up of extant cancer survivors and prospectively treated patients to characterize risks of SMNs and CVD in terms of radiation dose and type; 2) biological sample collection to integrate epidemiological studies with molecular and genetic evaluations; 3) investigation of interactions between radiotherapy and other potential confounding factors, such as age, sex, race, tobacco and alcohol use, dietary intake, energy balance, and other cofactors, as well as genetic susceptibility; 4) focusing on adolescent and young adult cancer survivors, given the sparse research in this population; and 5) construction of comprehensive risk prediction models for SMNs and CVD to permit the development of follow-up guidelines and prevention and intervention strategies.

Can the risk of secondary cancer induction after breast conserving therapy be reduced using intraoperative radiotherapy (IORT) with low-energy x-rays?

BACKGROUND

Radiation induced secondary cancers are a rare but severe late effect after breast conserving therapy. Intraoperative radiotherapy (IORT) is increasingly used during breast conserving surgery. The purpose of this analysis was to estimate secondary cancer risks after IORT compared to other modalities of breast radiotherapy (APBI - accelerated partial breast irradiation, EBRT - external beam radiotherapy).

METHODS

Computer-tomography scans of an anthropomorphic phantom were acquired with an INTRABEAM IORT applicator (diameter 4 cm) in the outer quadrant of the breast and transferred via DICOM to the treatment planning system. Ipsilateral breast, contralateral breast, ipsilateral lung, contralateral lung, spine and heart were contoured. An INTRABEAM source (50 kV) was defined with the tip of the drift tube at the center of the spherical applicator. A dose of 20 Gy at 0 mm depth from the applicator surface was prescribed for IORT and 34 Gy (5 days × 2 × 3.4 Gy) at 10 mm depth for APBI. For EBRT a total dose of 50 Gy in 2 Gy fractions was planned using two tangential fields with wedges. The mean and maximal doses, DVHs and volumes receiving more than 0.1 Gy and 4 Gy of organs at risk (OAR) were calculated and compared. The life time risk for secondary cancers was estimated according to NCRP report 116.

RESULTS

IORT delivered the lowest maximal doses to contralateral breast (< 0.3 Gy), ipsilateral (1.8 Gy) and contralateral lung (< 0.3 Gy), heart (1 Gy) and spine (< 0.3 Gy). In comparison, maximal doses for APBI were 2-5 times higher. EBRT delivered a maximal dose of 10.4 Gy to the contralateral breast and 53 Gy to the ipsilateral lung. OAR volumes receiving more than 4 Gy were 0% for IORT, < 2% for APBI and up to 10% for EBRT (ipsilateral lung). The estimated risk for secondary cancer in the respective OAR is considerably lower after IORT and/or APBI as compared to EBRT.

CONCLUSIONS

The calculations for maximal doses and volumes of OAR suggest that the risk of secondary cancer induction after IORT is lower than compared to APBI and EBRT.

Frequency of certain established risk factors in soft tissue sarcomas in adults: a prospective descriptive study of 658 cases

Soft tissue sarcomas are rare tumours with infrequent identified aetiological factors. Several genetic syndromes as well as previous radiation therapy and/or chronic lymphoedema have been suspected to predispose to some soft tissue sarcomas. Between January 1997 and September 2005, we carried out a prospective descriptive study to estimate the frequency of some particular etiological factors among 658 patients with soft tissue sarcomas. Sarcomas associated with a clinically identified genetic disease represent 2.8% out of all cases (95%CI: 1.5–3.8%). Most of these cases (14/19) are related to Recklinghausen neurofibromatosis. Radiation-induced sarcomas represent 3.3% out of all cases (95%CI: 1.7–5.1%). Most of these cases (9/22) are related to prior breast cancer treatment. We had observed only 1 case of Stewart-Treves syndrome. Liposarcoma, the most frequent histological subtype observed, is not associated with any particular aetiological entity. Finally, most of the adult soft tissue sarcomas are not related to any classical clinically identified genetic disease or previous radiation therapy and/or chronic lymphoedema risk factors. Frequency of underlying genetic syndrome which may predispose to soft tissue sarcomas could be higher than previously reported.

Risk of second cancer after initial treatment of breast cancer: An Osaka Cancer Registry Database study

In the present study, the association between the incidence of second cancer and initial treatment for primary breast cancer was investigated using the Osaka Cancer Registry in Japan. We selected 45,575 patients diagnosed with breast cancer between January 1975 and December 2003. Information on initial cancer treatment and second cancer was obtained from the Osaka Cancer Registry. Patients were classified according to initial treatment (chemo-, hormone, or radiotherapy, or no treatment). We calculated the incidence rate ratio of second cancers in patients classified by treatment for the first cancer. The effects of treatment adjusted for covariates on second cancers were examined using stratified analyses and a Cox proportional hazard model. The final number of 33,043 subjects had a mean duration of follow-up of 5.2±4.3 years, during which 1,857 second cancers were diagnosed. For hormone therapy, the incidence rate ratio (IRR) of all second cancers was 0.64 [95% confidence interval (CI), 0.58-0.70], and that of corpus uteri cancer was 3.04 (95% CI, 1.78-5.19). The multivariate analysis revealed that the IRR of corpus uteri cancer associated with hormone therapy was 2.53 (95% CI, 1.41‑4.55). The incidence rate of all second cancers associated with initial treatment was lower than that associated with no treatment. Only second corpus uteri cancer may be related to hormone therapy.

Second malignancies in breast cancer patients following radiotherapy: a study in Florence, Italy

INTRODUCTION

Patients diagnosed with breast cancer are often treated with surgery followed by radiation therapy. In this paper, we evaluate the effect that radiotherapy may have had on the subsequent risk of second malignancies, including the possible influences of age at treatment and menopausal status.

METHODS

In order to evaluate the long-term consequences of radiotherapy, a cohort study was conducted based on clinical records for 5,248 women treated for breast cancer in Florence (Italy), with continuous follow-up from 1965 to 1994. The Cox proportional hazards model for ungrouped survival data was used to estimate the relative risk for second cancer after radiotherapy.

RESULTS

This study indicated an increased relative risk of all second cancers combined following radiotherapy (1.22, 95% CI: 0.88 to 1.69). The increased relative risk appeared five or more years after radiotherapy and appeared to be highest amongst women treated after the menopause (1.61, 95% CI: 1.13 to 2.29). Increased relative risks were observed specifically for leukaemia (8.13, 95% CI: 0.96 to 69.1) and other solid cancers (1.84, 95% CI: 1.06 to 3.16), excluding contralateral breast cancer. For contralateral breast cancer, no raised relative risk was observed during the period more than five years after radiotherapy.

CONCLUSIONS

The study indicated a raised risk of second malignancies associated with radiotherapy for breast cancer, particularly for women treated after the menopause.

Accelerated Partial Breast Irradiation (APBI): A review of available techniques

Breast conservation therapy (BCT) is the procedure of choice for the management of the early stage breast cancer. However, its utilization has not been maximized because of logistics issues associated with the protracted treatment involved with the radiation treatment. Accelerated Partial Breast Irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Hence because of the small volume of irradiation a higher dose can be delivered in a shorter period of time. There has been growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy and intra-operative radiation therapy (IORT). Balloon-based brachytherapy approaches include Mammosite, Axxent electronic brachytherapy and Contura, Hybrid brachytherapy devices include SAVI and ClearPath. This paper reviews the different techniques, identifying the weaknesses and strength of each approach and proposes a direction for future research and development. It is evident that APBI will play a role in the management of a selected group of early breast cancer. However, the relative role of the different techniques is yet to be clearly identified.

Predictors of competing mortality in early breast cancer

BACKGROUND

Death in the absence of disease recurrence (competing mortality) is an important determinant of disease-free survival (DFS) in early breast cancer. The authors sought to identify predictors of this event using competing risks modeling.

METHODS

A cohort study was made of 1231 consecutive women with stage I to II invasive breast cancer diagnosed between 1986 and 2004, treated with breast conservation therapy. Median follow-up was 82 months. The authors used a parametric competing risks regression model to analyze factors associated with the cumulative incidence of competing mortality. They generated a risk score from the model coefficient estimates and stratified patients according to low and high risk score for analysis.

RESULTS

Ten-year DFS was 69.7% (95% confidence interval [CI], 66.2%-72.9%). The 10-year cumulative incidence of locoregional recurrence (LRR) was 4.4% (95% CI, 3.0%-5.8%), distant recurrence was 7.1% (95% CI, 5.4%-8.9%), and competing mortality was 18.7% (95% CI, 15.9%-21.6%). On multivariate analysis, competing mortality was associated with increasing age (hazard ratio [HR], 1.83 per 10 years; 95% CI, 1.58-2.12), black race (HR, 1.71; 95% CI, 1.17-2.51), and comorbid disease (HR, 1.93, 95% CI, 1.40-2.65). Ten-year cumulative incidences of competing mortality, locoregional recurrence, and distant recurrence for patients at low (n=638) versus high (n=593) risk of competing mortality were 7.2% versus 30.6% (P<.001), 4.4% versus 4.4% (P=.97), and 8.6% versus 5.6% (P=.12), respectively.

CONCLUSIONS

Competing mortality is an important event influencing 10-year DFS in early breast cancer and is associated with increasing age, black race, and comorbid disease. Stratifying patients according to competing mortality risk may be useful in designing clinical trials.

Do radiation-associated soft tissue sarcomas have the same prognosis as sporadic soft tissue sarcomas?

PURPOSE To determine the prognostic significance of histologic type in radiation-associated soft tissue sarcomas (RASs) and determine whether RASs are associated with an inferior prognosis compared with sporadic soft tissue sarcomas (STSs). PATIENTS AND METHODS One hundred thirty primary RASs were identified from 7,649 STS patients from 1982 to 2007. Multivariate analysis of clinicopathologic factors for disease-specific survival (DSS) was performed for RASs, and a multivariate analysis of radiation exposure was also performed for RASs and sporadic sarcomas. A matched-cohort analysis was performed for radiation-associated and sporadic malignant fibrous histiocytoma (MFH). Results Most RASs were high grade (83%), deep (87%), and truncal (61.5%). The median interval between radiation therapy and RAS development was 10 years (range, 1.3 to 74 years), which varied significantly by histologic type (P = .003). The 5-year DSS was 58%, and independent predictors were size > 5 cm, margin positivity, and histologic type. Multivariate analysis of histologic types of primary, high-grade radiation-associated and sporadic STSs showed that RAS was associated with a worse DSS (hazard ratio, 1.7; range, 1.1 to 2.4; P = .007). For pleomorphic MFH-the most common RAS type-the 5-year DSS was 44% versus 66% in a matched cohort of sporadic MFH patients (P = .07). DSS was significantly worse in primary RAS malignant peripheral nerve sheath tumors (MPNSTs) compared with unmatched sporadic MPNSTs (P = .001). CONCLUSION Histologic type, margin status, and tumor size are the most important independent predictors of DSS in patients with RASs. DSS in patients with primary RAS is significantly worse compared with sporadic STS independent of sarcoma histologic type.

Simultaneous integrated boost in breast conserving treatment of breast cancer: a dosimetric comparison of helical tomotherapy and three-dimensional conformal radiotherapy

BACKGROUND AND PURPOSE

To evaluate the dosimetry of helical tomotherapy (HT) and three-dimensional conformal radiotherapy (3D-CRT) in breast cancer patients undergoing whole breast radiation with simultaneous integrated boost (SIB) of the tumor bed.

MATERIAL AND METHODS

Thirteen patients with breast cancer treated by lumpectomy and requiring whole breast radiotherapy with tumor bed boost were planned using both HT and 3D-CRT using the field-in-field technique. The whole breast and tumor bed were prescribed 50.68 Gy and 64.4 Gy, respectively, in 28 fractions. Dosimetries for both techniques were compared.

RESULTS

Coverage of the whole breast was adequate with both techniques (V(95%)=96.22% vs. 96.25%, with HT and 3D-CRT, respectively; p=0.64). Adequate tumor bed coverage was also achieved, although it was significantly lower with HT (V(95%)=97.18% vs. 99.72%; p<0.001). Overdose of the breast volume outside the tumor bed was significantly lower with HT (V(54.23 Gy)=12.47% vs. 30.83%; p<0.001). Ipsilateral lung V(20 Gy) (6.34% vs. 10.17%; p<0.001), V(5 Gy) (16.54% vs. 18.53%; p<0.05) and mean dose (4.05 Gy vs. 6.36 Gy; p<0.001) were significantly lower with HT. In patients with left-sided tumors, heart V(30 Gy) (0.03% vs. 1.14%; p<0.05) and mean dose (1.35 Gy vs. 2.22 Gy; p<0.01) were significantly lower with HT, but not V(5 Gy). Contralateral breast V(5 Gy) (0.27% vs. 0.00%; p<0.01) and maximum dose were significantly increased with HT.

CONCLUSIONS

In breast cancer treated with SIB, both HT and 3D-CRT provided adequate target volume coverage and low heart doses. Tumor bed coverage was slightly lower with HT, but HT avoided unnecessary breast overdosage while improving ipsilateral lung dosimetry.

Secondary malignancies across the age spectrum

Development of a second malignancy is one of the most serious late effects in survivors of both childhood and adult-onset cancers. Patterns of second malignancy risk across the age spectrum can differ in terms of the types of second malignancies observed, magnitude of the risks, the latency period, associated risk factors, and modifying influences. Potential explanations for the varying risk patterns by age include differences in susceptibility of individual tissue/organ to carcinogenesis based on stage of development and level of tissue maturity, microenvironment, attained age, and lifestyle factors. A thorough understanding of these differences is essential when considering treatment modifications in newly diagnosed cancer patients who are aimed at reducing the risk of second malignancy and other late effects without compromising cure. Moreover, an understanding of the variations in second cancer risk according to age at treatment is important in customizing patient follow-up.

Bilateral angiosarcoma of the breast in a fourteen-year-old child

Malignant vascular tumors are rare and angiosarcomas of the breast in patients under 21 years of age are exceedingly uncommon. In this report an angiosarcoma in the breast of a 14-year-old girl is described. She died nine months after mastectomy with recurrent disease in the bones and the contralateral breast. The etiology of most primary angiosarcomas is unknown. Secondary angiosarcomas can develop after radiotherapy and chronic lymphedema. The histology of this angiosarcoma is illustrated.

Pathological confirmation of primary lung cancer following breast cancer

PURPOSE

Studies have shown that women who survive breast cancer have an increased risk of a future primary lung cancer, though many are based only on data recorded in tumor registries and none have conducted pathological confirmation. Previous studies and future use of large registries may be affected by misdiagnosis.

METHODS

Pathological analysis was conducted on tumors from 110 women with breast cancer followed by lung cancer using morphology, Estrogen Receptor-alpha (ER), and Thyroid Transcription Factor-1 (TTF1). We developed an algorithm to classify lung tumors as unlikely lung cancer (score=1) to likely lung cancer (score=5).

RESULTS

Mean time to diagnosis of lung cancer after breast cancer was 13 years. 76% of breast tumors and 20% of lung tumors were positive for ER and 51% of lung tumors were positive for TTF-1. 86% of the lung tumors were probable primaries, 7% were probable metastases from the breast, and 7% were of undetermined status. 70% of probable metastases had a latency of longer than 10 years.

CONCLUSION

Prior studies identifying the association of breast cancer and breast cancer treatments with lung cancer are likely to reflect true associations not confounded by misdiagnosis, as evidenced by the low rate of misclassification detected in this study. Analysis of the years of diagnosis suggests that latency may not be an accurate criterion for assignment of primary status, which could be significant in a clinical setting. These data may also benefit future retrospective studies using large registries.

Outcomes after breast conservation treatment with radiation in women with prior nonbreast malignancy and subsequent invasive breast carcinoma

PURPOSE

Little information has been reported regarding outcomes after treatment for patients with early-stage invasive breast cancer and a prior nonbreast malignancy. This report analyzes the outcomes in patients with Stage I and II breast cancer after breast conservation treatment (BCT) with a prior nonbreast malignancy.

METHODS AND MATERIALS

The study cohort comprised 66 women with invasive breast cancer and a prior nonbreast malignancy. All patients were treated with breast conservation surgery followed by definitive breast irradiation between 1978 and 2003. Median ages at diagnosis of invasive breast cancer and prior malignancy were 57 and 50 years, respectively. The median interval between the prior malignancy and breast cancer was 7.0 years. Median and mean follow-up times after BCT were 5.3 and 7.0 years.

RESULTS

The 5-year and 10-year overall survival rates were 94% (95% confidence interval [CI], 82-98%) and 78% (95% CI, 59-89%), respectively. There were 4 patients (6%) with local failure and 10 patients (15%) with distant metastases. The 10-year rate of local failure rate was 5% (95% CI, 2-16%) and freedom from distant metastases was 78% (95% CI, 61-88%). No obvious differences in survival or local control were noted compared with the reported results in the literature for patients with invasive breast cancer alone.

CONCLUSIONS

Both overall survival and local control at 5 and 10 years were comparable to rates observed in early-stage breast cancer patients without a prior malignancy. Prior nonbreast malignancy is not a contraindication to BCT, if the primary cancer is effectively controlled.

Solitary plasmocytoma: improvement in critical organs sparing by means of helical tomotherapy

PURPOSE

Helical tomotherapy (HT) was assessed in two patients with paramedullar solitary bone plasmocytoma. We compared doses delivered to critical organs, according HT plan or tridimensional conformal plan.

METHODS AND MATERIALS

One male (patient no. 1), 67 yr-old and one female (patient no. 2), 37-yr-old, with histologically, biologically and radiological confirmed paramedullar solitary plasmocytoma have been treated in our department between November 2007 and February 2008 using HT. The prescription dose was 40 Gy in 20 fractions. This HT treatment planning was compared with a routine dosimetric work that was executed for a standard conformal radiotherapy treatment planning.

RESULTS

Treatment tolerance was excellent, without any side effects. Both patients achieved 9-month complete remission. HT resulted in substantial critical organs sparing. For patient no. 1, dose delivered to 20% of the total intestine volume was reduced from 28 Gy for conformal radiotherapy to 13 Gy for HT. Radiation dose delivered to 20% of the left kidney was reduced from 25 Gy to 7 Gy. For patient no. 2, volume of left lung that received at least 20 Gy was 12% for conformal radiotherapy vs. 6% for HT.

CONCLUSIONS

For paramedullar solitary plasmocytoma, HT has the potential to significantly improve the quality of the dose distribution both in terms of better dose homogeneity within the planning target volume and more efficient sparing of critical organs.

Early experience of tomotherapy-based intensity-modulated radiotherapy for breast cancer treatment

AIMS

New technology - specifically intensity-modulated radiotherapy (IMRT) - is now being applied to breast radiotherapy and a recent dosimetric analysis confirmed the advantages of IMRT over 'wedge-only' plans. Such application to everyday practice raises new issues and here we present the early experience of IMRT-based breast irradiation in a single centre.

MATERIALS AND METHODS

We present cases of breast cancer treated by Tomotherapy-based IMRT, where the perceived advantages of IMRT are considerable. Cases presented are bilateral disease, left breast irradiation, pectus excavatum, prominent contralateral prosthesis and internal mammary chain disease. We discuss the practicalities of such treatment and the advantages over standard breast irradiation techniques.

RESULTS

Advantages include better conformity of treatment with lowering of dosages to underlying organs at risk, for example ipsilateral lung and heart. There is improved coverage of the planning target volume, including regional nodes, without field junction problems. Planning, quality assurance and treatment delivery are more time consuming than for standard breast irradiation and the low dose 'bath' is increased.

CONCLUSIONS

The standard radiotherapy tangential technique for breast/chest wall treatments has not significantly changed over many decades, whereas across many other tumour sites there have been great advances in radiotherapy technology. The dosimetric advantages of IMRT are readily apparent from our early experience. The wider spread of the lower dose zone (the low dose 'bath' of radiation) is a potential concern regarding late oncogenesis and methods to minimise such risks should be considered.

Subsequent malignant neoplasms in cancer survivors

In the past 3 decades, the number of cancer survivors in the United States has tripled, reaching approximately 10.7 million in 2004. Although cancer survivors now comprise about 3.5% of the population, subsequent malignancies among this high-risk group account for about 16% (or 1 in 6) of all cancer incidence. Multiple primary cancers can reflect the influence of antecedent cancer therapy, shared etiologic factors, environmental exposures, genetic susceptibility, lifestyle choices, other factors, and the combinations of effects, including gene-environment and gene-gene interactions. Survivors of individual types of primary cancers are at increased risk for distinctive types of subsequent neoplasms. Careful documentation of the magnitude and temporal patterns of these site-specific excess risks, as well as delineation of the contribution of treatment exposures and other factors, will facilitate the development of optimal follow-up plans. Management approaches should include patient education, screening, and prevention strategies. An improved understanding of those malignancies that are largely treatment-related will facilitate the formulation of customized therapeutic approaches for newly diagnosed cancer patients aimed at minimizing the risk of subsequent neoplasms and other late effects, without compromising cure rates.

Breast sarcoma--a review of diagnosis and management

Sarcoma of the breast is a rare condition. The biological differences from other primary breast tumours necessitate a corresponding difference in approach to diagnostic and management strategies. The rarity of the condition has made clinicopathological study difficult, with most series limited to less than 50 patients. We review the current literature on the diagnosis and management of breast sarcoma, and highlight areas of likely future development.

Helical tomotherapy for locoregional irradiation including the internal mammary chain in left-sided breast cancer: dosimetric evaluation

PURPOSE

To compare a standard 3- or 4-field technique to intensity modulated radiotherapy with helical tomotherapy (IMRT-HT) in the planning of locoregional breast radiation including the internal mammary chain (IMC).

METHODS AND MATERIALS

For 10 women with stage III left-sided breast cancer with a planning target volume (PTV) defined by the breast/chest wall and regional nodes, radiotherapy to a dose of 50 Gy in 25 fractions was planned using a standard 3- or 4-field technique and using IMRT-HT. Various metrics were extracted from dose-volume histograms, and were compared using the paired Student's t-test.

RESULTS

The PTV receiving at least 95% of the prescribed dose did not differ between the two plans, but the VD115% was significantly lower with IMRT-HT. The dose conformality was significantly better with IMRT-HT. The cardiac V30(Gy) was reduced with IMRT-HT. The mean lungs dose was lower with IMRT-HT, as well the V20(Gy). With IMRT-HT, a greater volume of contralateral breast was irradiated to 5 Gy, but a smaller volume of soft tissue received dose above 50 Gy.

CONCLUSIONS

Compared to a standard technique, IMRT-HT provides similar target coverage, improves dose conformality and dose homogeneity within the PTV, decreases mean lung dose and spares heart, lung and soft tissue from high dose exposure.

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.

Second primary in the contralateral breast after treatment of breast cancer

PURPOSE

To study the potential risk factors for contralateral breast cancer (CBC) in women after treatment of the primary breast cancer.

PATIENTS AND METHODS

Between January 1985 and December 1995, records of 1084 breast cancer patients at our institution were analyzed for incidence of CBC. In all the patients a detailed analysis was carried out with respect to age, disease stage, radiation therapy technique, dose, the use of chemotherapy or hormone therapy, and other clinical and/or pathologic characteristics. The Kaplan-Meier method was used to estimate the acturial rate of CBC. The Cox proportional hazard regression model was used to estimate the relative risk (RR) of CBC.

RESULTS

Up to December 2005, the median follow up was 12 years. Overall incidence of CBC was 4%. The 10 and 20 year acturial rate of CBC was 5.6% and 11.3%, respectively. The CBC rate at 10 and 20 year was 5.4% and 10.2%, respectively, for patients with mastectomy only and 5.1% and 9.7%, respectively, in the mastectomy plus RT group (p=0.3). In the subset of patients <45 years of age at the time of treatment, 10 and 20 year acturial rate of CBC was 5% and 9%, respectively, for patients who underwent mastectomy only and 6.3% and 11%, respectively, for patients treated with mastectomy plus RT (RR=1.4, 95% CI: 1.14-1.45, p=0.003). There was statistically significant lower rate of CBC in patients given adjuvant hormonal therapy (8.5%) as compared to those without hormonal therapy (14.3%, p=0.004) at 20 year. Women with family history of breast cancer had highest rate (15.3%) of CBC (RR=1.6, 95% CI: 1.12-1.27) at 20 years. The adjuvant use of chemotherapy did not significantly affect the risk of second malignancy.

CONCLUSION

There seems to be little risk of second malignancies in patients treated with mastectomy plus RT using modern techniques, compared with mastectomy only, that was only prevalent in patients <45 years of age. Family history of breast cancer seems to be the highest risk factor for CBC.

Is Multibeam IMRT Better Than Standard Treatment for Patients With Left-Sided Breast Cancer?

PURPOSE

When treatment intent is to include breast and internal mammary lymph nodes (IMNs) in the clinical target volume (CTV), a significant volume of the heart may receive radiation, which may result in late morbidity. The value of conformal intensity-modulated radiation therapy (IMRT) to avoid heart dose was studied.

METHODS AND MATERIALS

Breast, IMNs, and normal tissues were contoured for 30 consecutive patients previously treated with RT after lumpectomy for left-sided breast cancer. Eleven-beam, conformal, inverse-planned IMRT plans were developed and compared with best standard plans. Conformity Index (CI), Homogeneity Index (HI), and doses to normal tissues were compared.

RESULTS

Intensity-modulated RT significantly improved (two-sided paired t test) HI (0.95 vs. 0.74), CI (0.91 vs. 0.48), volume of the heart receiving more than 30 Gy (V30-heart) (1.7% vs. 12.5%), and volume of lung receiving more than 20-Gy (V20-left lung) (17.1% vs. 26.6%), all p < 0.001. The mean Healthy Tissue Volume (HTV = CT set - PTV) dose was similar between IMRT and best standard plans (6.0 and 6.9 Gy, respectively), but IMRT increased the volume of normal tissues receiving low-dose RT: V5-right lung (13.7% vs. 2.0%), V5-right breast (29.2% vs. 7.9%), and V5-HTV (31.7% vs. 23.6%), all p < 0.001. IMRT plans were generated in less than 60 min and treatment delivered in approximately 20 min, suggesting that this technique is clinically applicable.

CONCLUSIONS

IMRT significantly improved conformity and homogeneity for plans when the breast + IMNs were in the CTV. Heart and lung volume receiving high doses were decreased, but more healthy tissue received low doses. A simple algorithm based on amount of heart included in the standard plan showed limited ability to predict the benefit from IMRT.