Postoperative Tamoxifen for ductal carcinoma in situ: Cochrane systematic review and meta-analysis

Influence of tumor microenvironment on the different breast cancer subtypes and applied therapies

Despite the significant improvements made in breast cancer therapy during the last decades, this disease still has increasing incidence and mortality rates. Different targets involved in general processes, like cell proliferation and survival, have become alternative therapeutic options for this disease, with some of them already used in clinic, like the CDK4/6 inhibitors for luminal A tumors treatment. Nevertheless, there is a demand for novel therapeutic strategies focused not only on tumor cells, but also on their microenvironment. Tumor microenvironment (TME) is a very complex and dynamic system that, more than surrounding and supporting tumor cells, actively participates in tumor development and progression. During the last decades, it has become clear that the cellular and acellular components of TME differ between the various breast cancer subtypes and shape the differences regarding their severity and prognosis. The pivotal role of the TME in controlling tumor growth and influencing responses to therapy represents a potential source for novel targets and therapeutic strategies. In this review, we present a description of the multiple therapeutic options used for different breast cancer subtypes, as well as the influence that the TME may exert on the development of the disease and on the response to the distinct therapies, which in some cases may explain their failure by the occurrence of relapses and resistance. Furthermore, the ongoing studies focused on the use of TME components for developing potential cancer treatments are described.

Progression from ductal carcinoma in situ to invasive breast cancer: molecular features and clinical significance

Ductal carcinoma in situ (DCIS) represents pre-invasive breast carcinoma. In untreated cases, 25-60% DCIS progress to invasive ductal carcinoma (IDC). The challenge lies in distinguishing between non-progressive and progressive DCIS, often resulting in over- or under-treatment in many cases. With increasing screen-detected DCIS in these years, the nature of DCIS has aroused worldwide attention. A deeper understanding of the biological nature of DCIS and the molecular journey of the DCIS-IDC transition is crucial for more effective clinical management. Here, we reviewed the key signaling pathways in breast cancer that may contribute to DCIS initiation and progression. We also explored the molecular features of DCIS and IDC, shedding light on the progression of DCIS through both inherent changes within tumor cells and alterations in the tumor microenvironment. In addition, valuable research tools utilized in studying DCIS including preclinical models and newer advanced technologies such as single-cell sequencing, spatial transcriptomics and artificial intelligence, have been systematically summarized. Further, we thoroughly discussed the clinical advancements in DCIS and IDC, including prognostic biomarkers and clinical managements, with the aim of facilitating more personalized treatment strategies in the future. Research on DCIS has already yielded significant insights into breast carcinogenesis and will continue to pave the way for practical clinical applications.

A Short Post-Reattachment Ultrasensitive Window of Time in Human Cancer Cells as Therapeutic Target of Prolonged Low-Dose Administration of Specific Compounds

Prolonged low-dose administration (PLDA) of several FDA-approved drugs for noncancer conditions or dietary compounds is associated with a lower incidence of specific types of cancers and with the lower formation of metastasis. However, the underlying mechanism is unknown; there is a discrepancy between the concentration of drugs needed to kill cancer cells in vitro and the actual serum levels (10 and >1000 times lower) found in patients. In this study, we evaluated the hypothesis that clonogenicity may be the target of PLDA. We compared the effect of nigericin (NIG) and menadione (MEN) on the human A549 and H460 lung and MCF-7 and MDA-MB-231 breast cancer cell lines using routine MTT and colony forming assays (CFA). The ability of both NIG and MEN to eliminate 100% of cancer cells was at least 2-10 times more potent in CFA compared to MTT assays. Our results revealed the existence of a short post-reattachment window of time when cancer cells growing at low density are more sensitive to PLDA of specific drugs likely by targeting clonogenic rather than proliferation pathways. This short ultrasensitive window of time (SUSWoT) was cell- and drug-type specific: the SUSWoT for NIG was present in H460, A549, and MDA-MB-231 cells but not evident in MCF-7 cells. Conversely, a similar SUSWoT for MEN was present in MCF-7, MDA-MD-231, and A549 cells but not evident in H460 cells. Our findings partially explain the decreased incidence of specific types of cancer by PLDA of FDA-approved drugs (or dietary compounds) for noncancer conditions.

Adherence to hormonal therapy after surgery among older women with ductal carcinoma in situ: Implications for breast cancer-related adverse health events

BACKGROUND

Evidence from randomized clinical trials (RCTs) shows that receipt of hormonal therapy after surgery for estrogen receptor-positive ductal carcinoma in situ (DCIS) reduces the risk of DCIS and contralateral invasive breast cancer (IBC) but not death from breast cancer. RCTs examined homogeneous samples, and therefore whether this evidence can be generalized to diverse populations is unclear.

METHODS

Population-based data from four state cancer registries (California, New Jersey, New York, and Texas) were analyzed on women aged 65 years and older newly diagnosed with DCIS who underwent surgery with or without radiation during the years 2006-2013. Registry records were merged with Medicare enrollment in Parts A and/or B and D (prescription drugs) and associated claims. Whether adherence to hormonal therapy was associated with adverse breast cancer-related health events was analyzed.

RESULTS

Achieving excellent adherence did not affect death from breast cancer. In contrast, the risk of developing a subsequent breast tumor was 6.24 percentage points (breast-conserving surgery [BCS] with radiation therapy [RT]) and 10.54 percentage points (BCS alone) lower for women with excellent versus low adherence (p < .00001). For excellent versus good adherence, the reduced risk among women who had BCS with and without RT was approximately 3 and 5 percentage points, respectively. A similar pattern emerged for the risk of IBC among women who achieved excellent versus good or low adherence, whereas good versus low adherence comparisons were not significant.

CONCLUSIONS

This analysis of a diverse population-based cohort of women with DCIS demonstrates that achieving excellent adherence to hormonal therapy is critical to minimizing the occurrence of developing subsequent breast tumors.

PLAIN LANGUAGE SUMMARY

Our analysis of a diverse population-based cohort of women with ductal carcinoma in situ demonstrates that achieving excellent adherence to hormonal therapy is critical to minimizing the occurrence of developing subsequent breast tumors.

Clinical Outcomes of Conservative Treatment for Low-Risk Ductal Carcinoma in Situ: A Systematic Review and Pooled Analysis

AIMS

The current gold standard of treatment for ductal carcinoma in situ (DCIS) is surgical resection with or without adjuvant radiotherapy. However, the increased detection and radical treatment of DCIS did not result in a declined incidence of invasive breast cancers, leading to the debate if DCIS has been overtreated. While ongoing randomised controlled trials on active surveillance of DCIS are still in progress, this systematic review aims to evaluate the best evidence on conservative treatment for DCIS from the literature.

MATERIALS AND METHODS

This systematic review was conducted in line with the PRISMA statement. We included all relevant studies published up to June 2022 for analysis. The primary outcomes were overall survival and breast cancer-specific survival (BCSS) of conservative treatment for DCIS.

RESULTS

Three studies, with a total of 34 007 women with low-risk DCIS, were included in the analysis. Active and conservative treatments both resulted in excellent 10-year BCSS, with no statistically insignificant difference (98.6% versus 96.0%, 31 478 women). One study comparing 5-year BCSS of active and conservative treatments only in subjects aged over 80 years also reported [AQ1]an insignificant difference (98.2% versus 96.0%, 2529 women). One study measuring 5- and 10-year overall survival between the treatment groups also reported [AQ1]an insignificant difference (5-year: 96.2% versus 92.4%; 10-year: 85.6% versus 86.7%, 31 106 women).

CONCLUSION

BCSS between active and conservative treatment for women with low-risk DCIS is both excellent and comparable, suggesting that conservative treatment is a possible alternative without compromising survival.

Identifying recurrences and metastasis after ductal carcinoma in situ (DCIS) of the breast

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumour that has the potential to progress to invasive ductal carcinoma (IDC). Thus, it represents a treatment dilemma: alone it does not present a risk to life, however, left untreated it may progress to a life-threatening condition. Current clinico-pathological features cannot accurately predict which patients with DCIS have invasive potential, and therefore clinicians are unable to quantify the risk of progression for an individual patient. This leads to many women being over-treated, while others may not receive sufficient treatment to prevent invasive recurrence. A better understanding of the molecular features of DCIS, both tumour-intrinsic and the microenvironment, could offer the ability to better predict which women need aggressive treatment, and which can avoid therapies carrying significant side-effects and such as radiotherapy. In this review, we summarise the current knowledge of DCIS, and consider future research directions.

Metastases after mastectomy for ductal carcinoma in situ of the male breast; A case report

Introduction

and importance: Male breast cancer is a rare entity. Ductal carcinoma in situ (DCIS), constituting 10% of all male breast cancer, is confined within the breast ducts and lobules, rarely metastasizing and even less so after mastectomy.

Case presentation

A 71 years old male with no history of trauma presented with pain, swelling, and deformity of the left arm. He had continuous back pain for 6 months and a history of mastectomy of the right breast. Fracture of shaft of the left humerus was detected on X-ray. Computed tomography (CT) showed multiple vertebral metastases later confirmed to be metastasized from the breast by biopsy. Tumor cells were progesterone receptor (PR) positive, estrogen receptor (ER) negative, and human epidermal growth factor receptor 2 (HER2) negative. The fracture was treated and the patient was kept on Tamoxifen. On follow-up after four months, the patient is doing well with relief of back pain.

Clinical discussion

Despite mastectomy and the histopathological diagnosis of pure DCIS, distant metastases can occur even in absence of locoregional recurrence. Therefore, the aggressive phenotype of DCIS rather than diagnostic or treatment variables can be thought to bring worse outcome in the form of metastases. Early hormonal status identification and hormone therapy could result in a better outcome.

Conclusion

Skeletal metastases should be strongly suspected in patients presenting with bone pain and having a history of DCIS of the breast, even after mastectomy. Even though distant metastasis after mastectomy is rare, regular follow-up and surveillance is necessary.

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Male breast cancer is a rare entity.

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Ductal Carcinoma In situ (DCIS) is confined within ducts and lobules and rarely metastasizes.

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Aggressive phenotype of DCIS may be responsible for metastases rather than diagnostic or treatment variables.

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Regular follow up and surveillance is necessary after mastectomy for pure DCIS.

Hormone Receptor Subtype in Ductal Carcinoma in Situ: Prognostic and Predictive Roles of the Progesterone Receptor

Background

We investigated the prognostic and predictive roles of the hormone receptor (HRc) subtype in patients with ductal carcinoma in situ (DCIS). We focused on identifying the roles of the progesterone receptor (PR) independent of estrogen receptor (ER) status.

Methods

Nationwide data of 12,508 female patients diagnosed with DCIS with a mean follow‐up period of 60.7 months were analyzed. HRc subtypes were classified as ER−/PR−, ER−/PR+, ER+/PR−, and ER+/PR+ based on ER and PR statuses. The Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

The ER+/PR+ group showed better prognoses than the ER+/PR− and ER−/PR− groups in the patients who received tamoxifen therapy (p = .001 and p = .031, respectively). HRc subtype was an independent prognostic factor (p = .028). The tamoxifen therapy group showed better survival than the patients who did not receive tamoxifen, but only in the ER+/PR+ subgroup (p = .002). Tamoxifen therapy was an independent prognostic factor (HR, 0.619; 95% CI, 0.423 − 0.907; p = .014). PR status was a favorable prognostic factor in patients with DCIS who received tamoxifen therapy (p < .001), and it remained a prognostic factor independent of ER status (HR, 0.576; 95% CI, 0.349 − 0.951; p = .031).

Conclusion

The HRc subtype can be used as both a prognostic and predictive marker in patients with newly diagnosed DCIS. Tamoxifen therapy can improve overall survival in the ER+/PR+ subtype. PR status has significant prognostic and predictive roles independent of ER status. Testing for the PR status in addition to the ER status is routinely recommended in patients with DCIS to determine the HRc subtype in clinical settings.

Implications for Practice

The hormone receptor (HRc) subtype was an independent prognostic factor, and the estrogen receptor (ER)+/progesterone receptor (PR) + subtype showed a better survival in patients with ductal carcinoma in situ (DCIS) who received tamoxifen therapy. PR was an independent prognostic factor independent of ER, and PR was a favorable prognostic factor in patients with DCIS who received tamoxifen therapy. The HRc subtype could be used as both a prognostic and predictive marker in patients with newly diagnosed DCIS. Testing of PR status in addition to ER status is routinely recommended for patients with DCIS to determine the HRc subtype in clinical settings.

This study investigated the prognostic and predictive roles of the hormone receptor subtype in patients with newly diagnosed ductal carcinoma in situ, focusing on the prognostic and predictive values of progesterone receptor status independent of estrogen receptor status. The prognostic effect of tamoxifen therapy was also investigated

Cost-Effectiveness of Adjuvant Treatment for Ductal Carcinoma In Situ

PURPOSE

Ductal carcinoma in situ (DCIS) accounts for 20% of breast cancer cases in the United States and is potentially overtreated, leading to high expenditures and low-value care. We conducted a cost-effectiveness analysis evaluating all adjuvant treatment strategies for DCIS.

METHODS

A Markov model was created with six competing treatment strategies: observation, tamoxifen (TAM) alone, aromatase inhibitor (AI) alone, radiation treatment (RT) alone, RT + TAM, and RT + AI. Baseline recurrence rates were modeled using the NSABP B17 and RTOG 9804 trials for standard-risk and good-risk DCIS, respectively. Relative risk reductions and adverse event rates for each treatment strategy were derived from meta-analyses of large randomized trials. We used a willingness-to-pay threshold of $100,000 in US dollars/quality-adjusted life-year and a lifetime horizon for two cohorts of women, age 40 and 60 years. Comprehensive sensitivity analyses evaluated the robustness of base-case results.

RESULTS

RT alone was cost-effective for patients with standard-risk DCIS, and observation was cost-effective for patients with good-risk DCIS, across both age groups. Strategies including TAM or AI resulted in fewer quality-adjusted life-years than observation, because of the prolonged decrement in quality of life outweighing the modest benefit in ipsilateral risk reduction. In sensitivity analysis, RT alone was cost-effective for age 40, good-risk patients when ipsilateral risk reduction matched that of the RTOG 9804 trial, there was minimal increased risk of contralateral breast secondary malignancy, or there was strong patient willingness to pursue RT.

CONCLUSION

Our findings suggest that cost-effective and clinically optimal treatment strategies are RT alone for standard-risk DCIS and observation for good-risk DCIS, with personalization on the basis of patient age and preference for RT. Hormonal therapy is likely suboptimal for most patients with DCIS.

Grading variation in 2,934 patients with ductal carcinoma in situ of the breast: the effect of laboratory- and pathologist-specific feedback reports

BACKGROUND

Histologic grade of ductal carcinoma in situ of the breast (DCIS) may become the single biomarker that decides whether patients will be treated. Yet, evidence shows that grading variation in daily practice is substantial. To facilitate quality improvement, feedback reports, in which laboratory-specific case-mix adjusted proportions per grade were benchmarked against other laboratories, were sent to the individual laboratories by March 1, 2018. One year later, the effect of these feedback reports on inter-laboratory variation was studied.

METHODS

Synoptic pathology reports of all pure DCIS resection specimens between March 1, 2017 and March 1, 2019 were retrieved from PALGA (the nationwide Dutch pathology registry). Laboratory-specific proportions per grade were compared to the overall proportion in the year before and after feedback. The absolute deviation for all three grades at once, represented by the overall deviation score (ODS), was calculated as the sum of deviations from the grade-specific overall proportions. Case-mix adjusted, laboratory-specific odds ratios (ORs) for high- (grade III) versus low-grade (grade I-II) DCIS were obtained by multivariable logistic regression.

RESULTS

Overall, 2954 DCIS reports from 31 laboratories were included. After feedback, the range between laboratories decreased by 22 and 6.5% for grades II and III, while an increase of 6.2% was observed for grade I. Both the mean ODS (27.2 to 24.1%) and maximum ODS (87.7 to 59.6%) decreased considerably. However, the range of case-mix adjusted ORs remained fairly stable and substantial (0.39 (95% CI: 0.18-0.86) to 3.69 (95% CI: 1.30-10.51)).

CONCLUSION

A promising decrease in grading variation was observed after laboratory-specific feedback for DCIS grades II-III, while this was not observed for DCIS grade I. Overall, grading variation remained substantial which needs to be addressed considering its clinical implications. Nationwide consensus on a classification, and training of (expert breast) pathologists, for example by e-learning, may help to further improve grading standardization.

The challenge of avoiding over- and under-treatment in older women with ductal cancer in situ: A scoping review of existing knowledge gaps and a meta-analysis of real-world practice patterns

Ductal cancer in situ (DCIS) is mainly a screen-detected disease and although the risk for breast cancer is age-dependent, most screening programs do not include women over the age of 75 years. Older women are usually excluded from clinical trials and treatment practices are largely based on observational studies or extrapolation of trial results from younger patients, leading to either over- or under-treatment of this population. We systematically reviewed available electronic databases for DCIS treatment patterns and outcomes in older patients 15 years. Inclusion criteria allowed for randomised controlled trials, cohort studies, case-control and cross-sectional studies, as well as meta-analyses, systematic reviews and position papers. Results showed that, although elderly are not necessarily frail, they are generally treated as such by physicians, aiming to de-escalate therapeutic interventions. After adjusting for frailty, age seems to be a significant factor for less surgery; however, older women with DCIS are more probable to receive surgery than their counterparts with early invasive cancer. DCIS biology and subtypes are independent risk factors for local recurrence or progression to invasive carcinoma, if DCIS is under-treated. The end-benefit of surgery, radio- and endocrine-therapy depend on additional parameters, such as life expectancy, co-morbidities and competing risks of death. Screen-detected DCIS in older women is a challenging clinical problem, mainly due to the lack of high-level data. Therapeutic strategies should be tailored to life expectancy and performance status, DCIS features and patient preference, aiming at combining optimal oncological outcomes with maintenance of quality of life.

Ductal carcinoma in situ: to treat or not to treat, that is the question

Ductal carcinoma in situ (DCIS) now represents 20-25% of all 'breast cancers' consequent upon detection by population-based breast cancer screening programmes. Currently, all DCIS lesions are treated, and treatment comprises either mastectomy or breast-conserving surgery supplemented with radiotherapy. However, most DCIS lesions remain indolent. Difficulty in discerning harmless lesions from potentially invasive ones can lead to overtreatment of this condition in many patients. To counter overtreatment and to transform clinical practice, a global, comprehensive and multidisciplinary collaboration is required. Here we review the incidence of DCIS, the perception of risk for developing invasive breast cancer, the current treatment options and the known molecular aspects of progression. Further research is needed to gain new insights for improved diagnosis and management of DCIS, and this is integrated in the PRECISION (PREvent ductal Carcinoma In Situ Invasive Overtreatment Now) initiative. This international effort will seek to determine which DCISs require treatment and prevent the consequences of overtreatment on the lives of many women affected by DCIS.

[Decision making factors of the management of ductal carcinoma in situ of the breast with microinvasion]

INTRODUCTION

Microinvasive in situ ductal carcinomas of the breast are rare and of good prognosis. They are grouped with early stage invasive carcinomas in the TNM 2017 classification. This study assessed practitioners' treatment decisions and their justifications in comparison to the literature.

MATERIALS AND METHODS

Three clinical cases were evaluated by anonymous forms regarding sentinel node decisions, tumour bed boost irradiation and hormone therapy.

RESULTS

Sentinel lymph node was performed by 93.1%, 100% and 44.4% of the practitioners respectively. Radiation boost was a treatment option chosen by 62.1% and 61.1% of practitioners in both clinical cases. Hormone therapy was advocated for 65.5%, 94.7% and 50.0% patients depending on the clinical case.

CONCLUSION

The therapeutic attitude proposed in microinvasive breast carcinomas was heterogeneous in this study, reflecting the absence of specific recommendations. In view of the existing literature, it is not currently possible to propose recommendations for these three therapeutic options. Prospective cohorts and meta-analyses of the microinvasive subgroup could provide answers.

A retrospective alternative for active surveillance trials for ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) of the breast is a nonobligate precursor of invasive breast cancer, accounting for 20 % of screen-detected breast cancers. Little is known about the natural progression of DCIS because most patients undergo surgery upon diagnosis. Many DCIS patients are likely being overtreated, as it is believed that only around 50 % of DCIS will progress to invasive carcinoma. Robust prognostic markers for progression to invasive carcinoma are lacking. In the past, studies have investigated women who developed a recurrence after breast-conserving surgery (BCS) and compared them with those who did not. However, where there is no recurrence, the patient has probably been adequately treated. The present narrative review advocates a new research strategy, wherein only those patients with a recurrence are studied. Approximately half of the recurrences are invasive cancers, and half are DCIS. So-called "recurrences" are probably most often the result of residual disease. The new approach allows us to ask: why did some residual DCIS evolve to invasive cancers and others not? This novel strategy compares the group of patients that developed in situ recurrence with the group of patients that developed invasive recurrence after BCS. The differences between these groups could then be used to develop a robust risk stratification tool. This tool should estimate the risk of synchronous and metachronous invasive carcinoma when DCIS is diagnosed in a biopsy. Identification of DCIS patients at low risk for developing invasive carcinoma will individualize future therapy and prevent overtreatment.

The Assisi Think Tank Meeting Survey of post-mastectomy radiation therapy in ductal carcinoma in situ: Suggestions for routine practice

BACKGROUND

Risk factors for local recurrence after mastectomy in ductal carcinoma in situ (DCIS) emerged as a grey area during the second "Assisi Think Tank Meeting" (ATTM) on Breast Cancer.

AIM

To review practice patterns of post-mastectomy radiation therapy (PMRT) in DCIS, identify risk factors for recurrence and select suitable candidates for PMRT.

METHODS

A questionnaire concerning DCIS management, focusing on PMRT, was distributed online via SurveyMonkey.

RESULTS

142 responses were received from 15 countries. The majority worked in academic institutions, had 5-20 years work-experience and irradiated <5 DCIS patients/year. PMRT was more given if: surgical margins <1 mm, high-grade, multicentricity, young age, tumour size >5 cm, skin- or nipple- sparing mastectomy. Moderate hypofractionation was the most common schedule, except after immediate breast reconstruction (57% conventional fractionation).

CONCLUSIONS

The present survey highlighted risk factors for PMRT administration, which should be further evaluated.

Comparative Effectiveness of Surgical Options for Patients with Ductal Carcinoma In Situ: An Instrumental Variable Approach

CONTEXT

Many patients with ductal carcinoma in situ (DCIS) receive treatment that is too extensive.

OBJECTIVE

To take a holistic approach in comparing the effectiveness in cancer prevention between mastectomy and breast-conserving surgery (BCS) for patients with DCIS.

DESIGN

Female Kaiser Permanente Southern California members who underwent surgery for treatment of single primary DCIS from 2004 to 2014 were identified by the Kaiser Permanente Southern California cancer registry and HealthConnect database.

METHOD

Two-stage residual inclusion with the surgeon's preference of surgical procedure type as the instrumental variable was used to examine the effect of surgical choice on DCIS recurrence, breast cancer progression, and other cancer progression. Traditional Cox proportional hazards models were used for comparison.

RESULTS

Of qualified subjects, 72.2% underwent BCS and 27.8% underwent mastectomy. Patients were likelier to receive BCS if their surgeon preferred to perform BCS in the past 5 years (odds ratio = 1.02, 95% confidence interval = 1.02-1.03). Although traditional Cox proportional hazards models suggested an association between BCS and higher risk of DCIS recurrence, no significant effect was observed when we adjusted for endogeneity. Neither model showed significant differences between mastectomy and BCS in progression of any cancer.

CONCLUSION

No significant benefit was observed with a more aggressive surgical procedure in preventing DCIS recurrence or cancer progression in a diverse population. Many patients with DCIS could benefit from BCS with preservation of their body image. Breast conservation followed-up with cancer surveillance is a rational approach to ensure affordable, effective care for patients with DCIS.

Ductal carcinoma in situ - update on risk assessment and management

Ductal carcinoma in situ (DCIS) accounts for ~20-25% of breast cancers. While DCIS is not life-threatening, it may progress to invasive carcinoma over time, and treatment intended to prevent invasive progression may itself cause significant morbidity. Accurate risk assessment is therefore necessary to avoid over- or undertreatment of an individual patient. In this review we will outline the evidence for current management of DCIS, discuss approaches to DCIS risk assessment and challenges facing identification of novel DCIS biomarkers.

Hypofractionation Is an Acceptable Alternative to Conventional Fractionation in the Treatment of Postlumpectomy Ductal Carcinoma In Situ With Radiotherapy

PURPOSE

The standard dose of postlumpectomy radiotherapy (RT) for ductal carcinoma in situ (DCIS) is 50 Gy in 25 fractions using conventional fractionation (CF). However, in invasive carcinoma, hypofractionation (HF) with 40 to 42.6 Gy in 15 to 16 fractions has largely become a standard of care. The purpose of this study was to review the management of postlumpectomy DCIS in terms of RT dose-fractionation and its impact on local recurrence (LR), in one of the largest Canadian academic centers.

METHODS AND MATERIALS

Between 2003 and 2008, a total of 348 women with DCIS were treated with postlumpectomy RT. Patient characteristics, histopathology, dose-fractionation, use of endocrine therapy, local, regional, contralateral breast recurrences, and cause of death were collected. Local recurrence-free survival was determined. Univariate and multivariate analyses were performed to identify risk factors for LR.

RESULTS

The median age of the cohort was 59 years. Two hundred two (58%) patients received CF and 146 (42%) HF. Initially, the yearly proportion of HF was 34%, but increased up to 68% since 2007. Estrogen receptor was positive in 195 patients, and 43% of those received endocrine therapy. With a median follow-up of 64.8 months, 36 LRs were detected. The 5-year local recurrence-free survival rate was 94% for the HF group versus 91% for the CF group (P = .80). On multivariate analysis, only the use of endocrine therapy showed a trend towards decreasing LR (hazard ratio, 0.44; 95% confidence interval, 0.18-1.08; P = .07).

CONCLUSIONS

The utilization of HF for DCIS postlumpectomy has increased over time and is a valid option as it results in similar rates of local control.

The impact of in situ breast cancer and family history on risk of subsequent breast cancer events and mortality - a population-based study from Sweden

Background

The clinical behavior of in situ breast cancer is incompletely understood and several factors have been associated with invasive recurrence. The purpose of this study was to evaluate long-term risk of subsequent breast cancer and mortality among women diagnosed with in situ breast cancer, in relation to family history

Methods

Using the population-based Swedish Multi-Generation and Cancer Registers we identified 8111 women diagnosed with in situ breast cancer between 1980 and 2004. We used standardized incidence ratios (SIRs) to measure the relative risk of subsequent invasive or contralateral in situ breast cancer and standardized mortality ratios (SMRs) for relative risks of death.

Results

Among women diagnosed with in situ breast cancer, the cumulative 10-year and 20-year risk for subsequent contralateral or ipsilateral invasive cancer was approximately 10 % and 18 %, respectively. The risk of subsequent invasive breast cancer was increased more than 4-fold (SIR 4.6 (95 % CI 4.2 − 4.9)) among women with in situ breast cancer as compared to women in the general population and the risk of contralateral in situ breast cancer was increased almost 16-fold (SIR 16.0 (95 % CI 13.2–19.1)). Having a family history of breast cancer increased the risk of contralateral invasive breast cancer by almost 50 % (incidence rate ratio 1.5 (95 % CI 1.0–2.0)). Women under forty years old at diagnosis, without family history, had a 7-fold increased risk, and those with a family history had a 14-fold increased risk for subsequent invasive breast cancer with SIRs of 7.2 (95 % CI 4.8–10.5) and 14.3 (95 % CI 7.4–25.0), respectively. The overall risk of death in women with in situ breast cancer was significantly increased by 30 % compared to the general population but was highly dependent on the occurrence of a second invasive cancer event (SMR 1.3 (95 % CI 1.2–1.4)).

Conclusions

Among women with in situ breast cancer, a positive family history increases the risk of contralateral invasive breast cancer by almost 50 %. The risk of subsequent invasive breast cancer and mortality is substantially higher in younger women, which should be taken into account when planning their treatment and follow up.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0764-7) contains supplementary material, which is available to authorized users.

Updates in the treatment of ductal carcinoma in situ of the breast

PURPOSE OF REVIEW

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically diagnosed breast cancers. Currently, there is a trend to consider DCIS as a lesion for which treatment deescalation is advocated to avoid overtreatment, that is, radiotherapy in addition to breast-conserving surgery or even surgery at all.

RECENT FINDINGS

The long-term follow-up updates of the four first-generation randomized trials comparing lumpectomy with and without radiation therapy have confirmed that radiation halves the local failure rates. However, radiotherapy is not associated with a survival benefit just as affirmed by the recently published evaluation of the Surveillance, Epidemiology, and End Results registries database, including 108,196 women with DCIS. Nevertheless, the risk of dying of breast cancer increases about factor 18 after experience of an invasive local recurrence. That means at least some DCIS have the potential to progress to a life threatening disease. At the same time, none of the recently updated prospective trials that tested the outcome after excision alone in low-risk DCIS achieved a 10-year local failure rate below 10%.

SUMMARY

DCIS is not a uniform disease. Its clinical behaviour is heterogeneous, but up to date no citeria are available that allow a precise identification of patients with low or very low progression risk who do not need irradiation. Therefore, excision followed by radiotherapy is still the standard of care in patients undergoing breast conservation. Promising new approaches for risk estimation have to be validated prospectively before their use in daily practice can be recommended.

Subsequent risk of ipsilateral and contralateral invasive breast cancer after treatment for ductal carcinoma in situ: incidence and the effect of radiotherapy in a population-based cohort of 10,090 women

PURPOSE

To assess the effect of different treatment strategies on the risk of subsequent invasive breast cancer (IBC) in women diagnosed with ductal carcinoma in situ (DCIS).

METHODS

Up to 15-year cumulative incidences of ipsilateral IBC (iIBC) and contralateral IBC (cIBC) were assessed among a population-based cohort of 10,090 women treated for DCIS in the Netherlands between 1989 and 2004. Multivariable Cox regression analyses were used to evaluate associations of treatment with iIBC risk.

RESULTS

Fifteen years after DCIS diagnosis, cumulative incidence of iIBC was 1.9 % after mastectomy, 8.8 % after BCS+RT, and 15.4 % after BCS alone. Patients treated with BCS alone had a higher iIBC risk than those treated with BCS+RT during the first 5 years after treatment. This difference was less pronounced for patients <50 years [hazard ratio (HR) 2.11, 95 % confidence interval (CI) 1.35-3.29 for women <50, and HR 4.44, 95 % CI 3.11-6.36 for women ≥50, P interaction  < 0.0001]. Beyond 5 years of follow-up, iIBC risk did not differ between patients treated with BCS+RT or BCS alone for women <50. Cumulative incidence of cIBC at 15 years was 6.4 %, compared to 3.4 % in the general population.

CONCLUSIONS

We report an interaction of treatment with age and follow-up period on iIBC risk, indicating that the benefit of RT seems to be smaller among younger women, and stressing the importance of clinical studies with long follow-up. Finally, the low cIBC risk does not justify contralateral prophylactic mastectomies for many women with unilateral DCIS.

Variation in the management of ductal carcinoma in situ in the UK: Results of the Mammary Fold National Practice Survey

INTRODUCTION

Ductal carcinoma in situ (DCIS) accounts for approximately 10% of all newly-diagnosed breast cancers in the UK. The latest national guidelines were published in 2009 and may not reflect current best practice. We aimed to explore variation in the current management of DCIS to support the need for updated guidelines.

METHODS

A national practice questionnaire was developed by the Mammary Fold Academic Committee (MFAC) focussing on the pre, intra and post-operative management of DCIS. Trainees at UK breast units were invited to complete the questionnaire at their multidisciplinary team meeting to provide a comprehensive picture of current national practice.

RESULTS

76 of 144 UK breast units (52.8%) participated in the survey. Variation was observed in radiological pre-operative assessment with only 33/76 units (43.4%) performing routine ultrasound assessment of the tumour or axilla. There was no clear consensus regarding indications for mastectomy; multifocality (38.2%) and extensive microcalcifications (34.2%) were the most frequent indications. 34/76 units (44.7%) offered nipple sparing mastectomy. 33/76 units (43.3%) perform sentinel node biopsy in the presence of a palpable/mass lesion and 51/76 (67.1%) at the time of mastectomy. The most widely accepted pathological radial margin remained 2 mm (36.8%). The commonest factors in decision-making for radiotherapy were tumour grade (51.3%) and size (35.5%). Only 12 units (15.8%) routinely used the Van Nuys Prognostic Index. Approximately half of all breast units offer clinical long-term follow-up.

DISCUSSION

There is marked variation in the management of DCIS in the UK. Updated evidence-based guidelines may standardise practice and improve outcomes for patients.

Tamoxifen Initiation After Ductal Carcinoma In Situ

BACKGROUND

Endocrine therapy initiation after ductal carcinoma in situ (DCIS) is highly variable and largely unexplained. National guidelines recommend considering tamoxifen for women with estrogen receptor-positive (ER+) DCIS or who undergo excision alone. We evaluated endocrine therapy use after DCIS over a 15-year period in an integrated health care setting to identify factors related to initiation.

METHODS

Female Group Health Cooperative enrollees ages 18-89 years with a DCIS diagnosis during 1996-2011 were eligible for inclusion. Endocrine therapy was identified through pharmacy records. Tumor and treatment information were from tumor registry reports; demographics and other risk factors were from questionnaires and electronic medical records. Relative risks (RRs) and 95% confidence intervals (CIs) for endocrine therapy initiation were calculated using multivariable generalized linear models.

RESULTS

We identified 727 women with a DCIS diagnosis, including 163 (22%) who initiated endocrine therapy (149 tamoxifen, 14 aromatase inhibitor). Younger women were more likely to initiate endocrine therapy (RR 1.69; 95% CI 1.16-2.46 for ages 45-54 vs. 65-74 years). Compared with breast-conserving surgery (BCS) with radiation, women who had BCS alone (RR 0.46; 95% CI 0.25-0.84) or mastectomy (RR 0.54; 95% CI 0.39-0.75) were less likely to use endocrine therapy. ER testing increased from 4% of DCIS cases in 2001 to 71% in 2011; however, endocrine therapy initiation decreased from 58% of ER+ DCIS in 2001-2005 to 37% in 2009-2011.

CONCLUSION

Increasing ER testing since 2001 has not corresponded to parallel increases in endocrine therapy initiation. Age, surgery, and radiation were the primary factors associated with initiation.

IMPLICATIONS FOR PRACTICE

National guidelines recommend considering tamoxifen for women with ductal carcinoma in situ (DCIS) who are estrogen receptor-positive (ER+) or who undergo excision alone. In this study, the rapid increase in ER testing caused by tamoxifen's approval in 2000 did not lead to increases in endocrine therapy initiation, despite recognition of an increasing number of DCIS tumors as ER+ each year. Contrary to the suggested guidelines, women who had breast-conserving surgery without radiation were less likely to use tamoxifen than those who had radiation. Future Food and Drug Administration approval of new endocrine agents for DCIS (such as aromatase inhibitors) may provide an opportunity to reemphasize benefits by ER and surgery status.

Clinicopathological predictive factors for ipsilateral and contralateral events following initial surgery to treat ductal carcinoma in situ

BACKGROUND

Ipsilateral breast tumor recurrence (IBTR) after partial breast resection and contralateral breast tumor recurrence (CBTR) have been shown to occur relatively frequently in patients with ductal carcinoma in situ (DCIS). However, there is only limited data from Japanese institutes to support this.

METHODS

Of 301 consecutive DCIS patients, 179 patients underwent a mastectomy, and the other 122 underwent partial resection in the National Cancer Center Hospital, Tokyo, with a median follow-up period of 2,106 days. We reviewed clinicopathological parameters including age, menopausal status, body mass index, family history (FH) of breast cancer, tumor size, histological subtype, nuclear grade (NG), hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status, treatment, and the surgical margin status of partially resected specimens. The risk associated with each of these parameters for IBTR in 122 patients who underwent partial resections, and for CBTR in a total of 301 patients were calculated using Cox proportional hazard general linear models.

RESULTS

Of the 122 patients who underwent partial breast resection, IBTR occurred in 7 (5.7%). The risk of IBTR was higher or tended to be higher in younger patients or those with lower NG tumors, but did not change significantly with respect to margin status or irradiation. Amongst the entire cohort of 301 patients, CBTR occurred in 18 cases (6.0%). CBTR occurred significantly more frequently in patients with a FH of breast cancer and with HR+/HER2- subtype tumors by univariate analyses, and tumor subtype was an independent risk factor for CBTR by multivariate analysis.

CONCLUSIONS

The local recurrence rate was low following partial resection of DCIS. Younger age was a risk factor for IBTR, whereas the HR+/HER2- tumor subtype and a FH of breast cancer were risk factors for CBTR.