The effect of locoregional recurrence on survival and distant metastasis after conservative treatment for invasive breast carcinoma

Time-varying coefficients in a multivariate frailty model: Application to breast cancer recurrences of several types and death

During their follow-up, patients with cancer can experience several types of recurrent events and can also die. Over the last decades, several joint models have been proposed to deal with recurrent events with dependent terminal event. Most of them require the proportional hazard assumption. In the case of long follow-up, this assumption could be violated. We propose a joint frailty model for two types of recurrent events and a dependent terminal event to account for potential dependencies between events with potentially time-varying coefficients. For that, regression splines are used to model the time-varying coefficients. Baseline hazard functions (BHF) are estimated with piecewise constant functions or with cubic M-Splines functions. The maximum likelihood estimation method provides parameter estimates. Likelihood ratio tests are performed to test the time dependency and the statistical association of the covariates. This model was driven by breast cancer data where the maximum follow-up was close to 20 years.

Survival after locoregional recurrence or second primary breast cancer: impact of the disease-free interval

The association between the disease-free interval (DFI) and survival after a locoregional recurrence (LRR) or second primary (SP) breast cancer remains uncertain. The objective of this study is to clarify this association to obtain more information on expected prognosis. Women first diagnosed with early breast cancer between 2003–2006 were selected from the Netherlands Cancer Registry. LRRs and SP tumours within five years of first diagnosis were examined. The five-year period was subsequently divided into three equal intervals. Prognostic significance of the DFI on survival after a LRR or SP tumour was determined using Kaplan-Meier estimates and multivariable Cox regression analysis. Follow-up was complete until January 1, 2014. A total of 37,278 women was included in the analysis. LRRs or SP tumours were diagnosed in 890 (2,4%) and 897 (2,4%) respectively. Longer DFI was strongly and independently related to an improved survival after a LRR (long versus short: HR 0.65, 95% CI 0.48–0.88; medium versus short HR 0.81, 95% CI 0.65–1.01). Other factors related to improved survival after LRR were younger age (<70 years) and surgical removal of the recurrence. No significant association was found between DFI and survival after SP tumours. This is the first study to explore the association between the DFI and survival after recurrence in a nationwide population-based cancer registry. The DFI before a LRR is an independent prognostic factor for survival, with a longer DFI predicting better prognosis.

Risk factors for distant metastasis as a primary site of treatment failure in early-stage breast cancer

The aim of this study was to evaluate the risk factors for distant metastasis (DM) as a primary site of failure in early-stage breast cancer. Data from 294 patients diagnosed with pathologic stage I or II breast cancer between January 2000 and December 2005 were reviewed retrospectively. Median follow-up duration was 81.0 months (range, 18-135 months). The total number of patients with DM without evidence of locoregional recurrence was 20 and the median time between surgery and DM was 29 months (range, 9-79 months). Median survival time was 38 months (range, 22-77 months) after operation. HER-2 positivity (p=0.015), T stage of tumor (p=0.012), and number of involved lymph nodes (p=0.008) were significant predictors of DM in the univariable analysis. Number of involved lymph nodes [p=0.005, hazards ratio (HR): 1.741; 95% confidence interval (CI): 1.178-2.574] and HER-2 positivity (p=0.018, HR: 2.888; 95% CI: 1.201-6.941) had a statistically significant effect on DM-free survival in the multivariable analysis. A cautious evaluation may be helpful when patients with risk factors for DM have symptoms implying the possibility of DM. To reduce DM, applying intensive therapy is needed after curative surgery for patients with high risk for DM.

Multivariate frailty models for two types of recurrent events with a dependent terminal event: application to breast cancer data

Individuals may experience more than one type of recurrent event and a terminal event during the life course of a disease. Follow-up may be interrupted for several reasons, including the end of a study, or patients lost to follow-up, which are non informative censoring events. Death could also stop the follow-up, hence, it is considered as a dependent terminal event. We propose a multivariate frailty model that jointly analyzes two types of recurrent events with a dependent terminal event. Two estimation methods are proposed: a semiparametrical approach using penalized likelihood estimation where baseline hazard functions are approximated by M-s plines, and another one with piecewise constant baseline hazard functions. Finally, we derived martingale residuals to check the goodness-of-fit. We illustrate our proposals with a real dataset on breast cancer. The main objective was to model the dependency between the two types of recurrent events (locoregional and metastatic) and the terminal event (death) after a breast cancer.

Impact of local surgical treatment on survival in young women with T1 breast cancer: long-term results of a population-based cohort

The aim of this study was to analyze the effect of the type of local surgical treatment on survival in young women aged less than 40 years with T1 breast cancer. We analyzed data from 3,512 patients aged ≤40 years old who were diagnosed with T1 breast cancer from the Korean Breast Cancer Registry database between January 1988 and December 2006 and underwent either breast-conserving therapy (BCT) or mastectomy. The overall survival (OS) and breast-cancer-specific survival (BCSS) were compared between BCT and mastectomy. Of the 3,512 patients analyzed, 1,951 (55.6 %) underwent BCT, and 1,561 (44.4 %) underwent mastectomy. The median follow-up period was 111.0 (79.0-131.5) months. Overall, the 10-year OS rates for BCT and mastectomy were 95 and 92.1 %, respectively (p = 00004), and the 10-year BCSS rates for BCT and mastectomy patients were 96.9 and 94.9 %, respectively (p = 0.12). In node-negative patients, no significant difference was observed in either the OS (adjusted hazard ratio [HR] 1.072; 95 % CI, 0.750-1.5332, p = 0.704) or BCSS (adjusted HR 0.988; 95 % CI, 0.620-1.574, p = 0.960) rate between the BCT and mastectomy groups. In node-positive patients, no significant difference was observed in the OS (adjusted HR 1.634; 95 % CI, 0.982-2.272, p = 0.59) and BCSS (adjusted HR 1.410; 95 % CI, 0.755-2.633, p = 0.281) rates between the BCT and mastectomy groups. In this large, population-based analysis of young women with T1 breast cancer, the OS and BCSS were not different between BCT and mastectomy.

The impact of local and regional recurrence on distant metastasis and survival in patients treated with breast conservation therapy

Purpose

We evaluated the effect of local recurrence (LR) and regional recurrence (RR) on distant metastasis and survival in patients treated with breast conservation therapy (BCT).

Methods

We analyzed 907 patients who were treated for invasive breast cancer between 1993 and 2006. With 53 months of follow-up, 28 patients (3.1%) developed LR in the breast and 12 patients (1.3%) developed RR before distant metastasis. LR and RR were separated into four patterns to determine the prognostic relevance of recurrence site and time to recurrence: LR within 3 years (early LR), LR after 3 years (late LR), RR within 3 years (early RR), and RR after 3 years (late RR).

Results

Early LR (hazard ratio [HR], 4.76; p=0.003) and early RR (HR, 18.16; p<0.001) were independent predictors of distant metastasis. In terms of overall survival, early LR (HR, 5.24; p=0.002), and early RR (HR, 18.80; p<0.001) were significantly related with poor survival. Patients with late LR/RR had a similar favorable prognosis compared with patients who never experienced LR/RR.

Conclusion

The result suggests that time to LR/RR following BCT is a significant predictor developing a distant metastasis and surviving.

Different annual recurrence pattern between lumpectomy and mastectomy: implication for breast cancer surveillance after breast-conserving surgery

PURPOSE

To investigate the recurrence pattern and annual recurrence risk after breast-conserving surgery and compare them with those after mastectomy.

METHODS

This retrospective analysis included 6,135 consecutive unilateral breast cancer patients undergoing surgery in 1998-2008, with 847 lumpectomy patients and 5,288 mastectomy patients. Recurrence patterns were scrutinized and annual recurrence rates were calculated. Furthermore, a literature-based review including seven relevant studies was subsequently performed to confirm our single-institution data-based observations.

RESULTS

After lumpectomy, 50.9% of recurrences occurred within 3 years and 30.2% of recurrences were detected at 3-5 years; after mastectomy, 64.9% of recurrences occurred within 3 years and 20.4% occurred at 3-5 years. The major locoregional recurrence pattern after lumpectomy was ipsilateral breast tumor recurrence, which mainly (81.3%) occurred ≤5 years postsurgery but with a low incidence of 37.5% ≤3 years postsurgery. Annual recurrence curves indicated that the relapse peak after mastectomy emerged in the first 2 years; however, recurrence after lumpectomy increased annually with the highest peak near 5 years. By reviewing relevant studies, we confirmed our finding of different annual recurrence patterns for lumpectomy and mastectomy patients. The hazard ratio of dying for those recurring ≤5 years postlumpectomy relative to patients relapsing >5 years postlumpectomy was 4.62 (95% confidence interval, 1.05-20.28; p = .042).

CONCLUSIONS

Different recurrence patterns between mastectomy and lumpectomy patients imply that scheduling of surveillance visits should be more frequent during the 4-6 years after lumpectomy. Further prospective trials addressing the necessity of frequent and longer surveillance after lumpectomy are warranted.

The impact of adjuvant endocrine therapy on reducing the risk of distant metastases in hormone-responsive breast cancer

SUMMARY

The primary goal of systemic adjuvant therapy for breast cancer is to control the risk of recurrence following surgery, thereby improving long-term survival. For many years, tamoxifen has served as the standard adjuvant endocrine therapy for postmenopausal women with hormone-sensitive breast cancer. The entry of the third-generation aromatase inhibitors (AIs) exemestane, anastrozole and letrozole as adjuvant therapy has introduced several different treatment options. Indirect comparisons suggest that appreciable differences may exist between the AIs in terms of early risk reduction, especially the risk for early distant metastases. Possible differences in efficacy may be related to differences in potency. Two ongoing trials directly comparing two AIs - the Femara versus Anastrozole Clinical Evaluation and MA.27 - may provide further information.

The role of endocrine therapies in reducing risk of recurrence in postmenopausal women with hormone receptor-positive breast cancer

Hormone receptor-positive breast cancer is increasingly considered a chronic disease, as there remains an ongoing risk of local and distant relapse for years after diagnosis. While early recurrence risk peaks 2-3 years post diagnosis, the majority of breast cancer recurrences and deaths occur following 5 years of adjuvant tamoxifen. Aromatase inhibitors have achieved greater relative reductions in recurrence risk than tamoxifen alone and are now widely recommended as adjuvant therapy for postmenopausal women with hormone-sensitive breast cancer. Although both anastrozole and letrozole have demonstrated superior disease-free survival compared with tamoxifen, letrozole to date offers the greatest significant reduction in the risk of distant metastases in patients with hormone-sensitive breast cancer. Anastrozole and exemestane also reduce local and distant recurrence risk in the "switch setting" following 2-3 years of tamoxifen. Extended adjuvant letrozole, given after 5 years of tamoxifen, significantly reduces local and distant recurrence as well as mortality in patients with node-positive disease. Specialist nurses and nurse practitioners facilitate informed choice for breast cancer patients through explaining treatment options and side effects; they thus need an understanding of which treatment strategies reduce recurrence risk, especially the risk of distant metastases.

Evaluating distant metastases in breast cancer: from biology to outcomes

There is an urgent need to understand distant metastases in breast cancer as they are the most lethal form of recurrence and a major cause of mortality in patients. Some predictors for distant metastases, including nodal status, tumor grade, and hormonal status, are useful in identifying patients at increased risk for distant metastases. Adjuvant endocrine therapy has been the treatment of choice for postmenopausal women with hormone-sensitive breast cancer, and some therapies have shown significant reductions in the risk of distant metastases. Skeletal metastases in breast cancer are treated with bisphosphonates with a certain level of success. With more new agents undergoing clinical trials, a thorough review of the specific and long-term safety of these agents is essential, as is a better understanding of the deterioration in the quality of life and cost concerns of patients who develop distant metastases. Gene-expression profiling is a new entrant in the field of distant metastases diagnosis, which is largely successful in defining gene signatures that predict the development of distant metastases. This review will discuss the biology and the impact of distant metastases on outcomes for patients with breast cancer; it also encompasses the current status, emerging focus, and future perspectives in treatment of skeletal metastases in patients with breast cancer.

The role of postoperative radiotherapy in node negative breast cancer patients with pT3–T4 disease

AIMS

To evaluate the role of postmastectomy radiotherapy (PMRT) in patients with pT3-T4N0M0 breast cancer.

METHODS

156 patients with T3-T4N0M0 breast cancer were retrospectively analyzed.

RESULTS

Locoregional recurrences were seen in 17 of 156 patients with a median time for development of 27 months (5.7-248.7 months). Two of 9 patients who were not treated with post-operative radiation therapy had locoregional recurrence as compared with 16 of 147 patients receiving radiotherapy. In multivariate analysis, presence of locoregional recurrence was the only significant prognostic factor for overall survival (18% vs. 86%, p<0.001, RR=9.05). The patients with a median number of dissected lymph nodes >or=10 had a significantly better locoregional disease free survival rate as compared with patients with dissected lymph nodes <10 (90% vs. 78%, p=0.04). Chest wall recurrences were clearly higher in patients without chest wall RT since 5 of 49 patients without RT had recurrences in the chest wall region while only 4 of 107 who received chest wall RT had recurrence. However receiving RT to peripherical lymphatic regions had no additional effect on reducing recurrences in these regions (5% vs. 4%).

CONCLUSIONS

Due to the lack of phase III randomized trials directly addressing the role of postmastectomy radiotherapy in these stages, our series suggest that postmastectomy radiotherapy to the ipsilateral chest wall is recommended for patients with PT3N0 and T4N0 breast cancer. The need for irradiating axillary or supraclavicular region shall be neglected in patients who undergo sufficient axillary sampling.

Delaying Radiotherapy for the Delivery of Adjuvant Chemotherapy in the Combined Modality Treatment of Early Breast Cancer: Is It Disadvantageous and Could Combined Treatment be the Answer?

Women with early stage breast cancer are increasingly being treated with both adjuvant chemotherapy and radiotherapy. The optimal sequence of these two treatment modalities is yet to be defined. It remains controversial whether delaying radiotherapy in order to deliver chemotherapy compromises local disease control and survival. Consequently, clinical practice in the UK is divided, with a number of different combination schedules being used in an effort to bring forward the start of radiotherapy. In practice, however, any benefit in local control must be balanced against a potential increase in toxicity. A review of the current literature on the effect of radiotherapy delay is presented, together with data on the toxicity of combined chemo-radiotherapy schedules and recent data from clinical trials designed to determine the optimal sequencing of chemotherapy and radiotherapy.