Lymphovascular invasion, as a prognostic marker in patients with invasive breast cancer

Study of Tumor-Infiltrating Lymphocytes in Breast Carcinoma and Their Association With Pathological and Prognostic Factors and Pathological Tumor-Node-Metastasis (pTNM) Staging

OBJECTIVES

Breast carcinoma is the second most frequent type of cancer globally, with an estimated 2.08 million new carcinoma cases identified in 2018. Breast cancer prognosis is influenced by a number of variables, including the patient's age, morphological variant, stromal inflammatory reaction, elastotic, fibrotic focus, lymphovascular emboli, recurrence of tumor, etc. Recently, the morphological evaluation and extent of tumor-infiltrating lymphocytes (TIL) have also been studied in breast cancer. An attempt is being made to understand the role of TIL in determining the prognostication of carcinoma breast. Thus, the goal of the current academic study is to assess TIL in breast carcinoma.

MATERIALS AND METHOD

The study was performed at a medical institution's pathology department, which covered newly diagnosed cases of infiltrating ductal carcinoma of the breast on histopathology during the January to December 2019 time frame. The gross and hematoxyline-eosin-stained paraffin sections were studied for histopathological examination.

RESULTS

The study included 50 cases of infiltrating ductal carcinoma of the breast with a female-to-male ratio of 24:1. Stromal TIL was negative (0-10%) in 12 cases, while was positive (11-100 %) in 38 cases. The results of the receiver operating characteristic (ROC) curve study indicated that the specificity was 70.7% and the sensitivity was 85.3% when the cutoff of stromal TIL <11% was used to predict the live status of patients.

CONCLUSION

Stromal TIL is an important parameter that must be reported in breast carcinoma cases. Positive stromal TIL shows a statistically significant difference with pathological tumor-node-metastasis (pTNM) staging, tumor laterality, size of the tumor, and involvement of nipple and areola.

Significance of Serum Lactate Dehydrogenase as a Prognostic Marker and Outcome Predictor in Patients With Breast Cancer

Background Breast carcinoma has been the most prevalent cancer in women, with research-based evidence showing a significant rise in the incidence of cancer and related morbidity and mortality in the Indian subcontinent. The predictive value of plasmatic lactate dehydrogenase (LDH) levels has been studied in breast cancer. Numerous studies have connected high LDH values to a poor prognosis, increased risk of incidence, recurrence, and associated mortality in patients with breast carcinoma. This study aimed to assess the clinical profile of breast carcinoma and determine the correlation of serum lactate dehydrogenase levels with the stage of the disease and assessment of high-risk features using histopathology and immunohistochemistry. Methods A total of 75 patients with carcinoma breast were enrolled for this study and classified into two groups: upfront surgery and post-adjuvant therapy. Serum LDH levels were estimated a day before the surgery (baseline) and on postoperative days 1, 7, 14, and 30. The clinical tumor, node, metastasis (cTNM) staging was correlated with pathological tumor, node, metastasis TNM (pTNM) staging and immunohistochemistry findings. Results The clinical characteristics of breast cancer, serum LDH levels, and stage of the disease were collected and analyzed. A significant decreasing trend was noted in LDH values post-op days, and statistically significant higher LDH values were noted in the triple-negative group, positive lymph nodes, and positive lymphovascular invasion patients. Conclusion Regularly elevated levels or an unanticipated rise in serum LDH might indicate poor outcomes. Hence, this non-specific enzyme marker can be suggested to be used routinely to assess disease outcomes.

Prognostic Value of Salivary Biochemical Indicators in Primary Resectable Breast Cancer

Despite the fact that breast cancer was detected in the early stages, the prognosis was not always favorable. In this paper, we examined the impact of clinical and pathological characteristics of patients and the composition of saliva before treatment on overall survival and the risk of recurrence of primary resectable breast cancer. The study included 355 patients of the Omsk Clinical Oncology Center with a diagnosis of primary resectable breast cancer (T1-3N0-1M0). Saliva was analyzed for 42 biochemical indicators before the start of treatment. We have identified two biochemical indicators of saliva that can act as prognostic markers: alkaline phosphatase (ALP) and diene conjugates (DC). Favorable prognostic factors were ALP activity above 71.7 U/L and DC level above 3.93 c.u. Additional accounting for aspartate aminotransferase (AST) activity allows for forming a group with a favorable prognosis, for which the relative risk is reduced by more than 11 times (HR = 11.49, 95% CI 1.43-88.99, p = 0.01591). Salivary AST activity has no independent prognostic value. Multivariate analysis showed that tumor size, lymph nodes metastasis status, malignancy grade, tumor HER2 status, and salivary ALP activity were independent predictors. It was shown that the risk of recurrence decreased with menopause and increased with an increase in the size of the primary tumor and lymph node involvement. Significant risk factors for recurrence were salivary ALP activity below 71.7 U/L and DC levels below 3.93 c.u. before treatment. Thus, the assessment of biochemical indicators of saliva before treatment can provide prognostic information comparable in importance to the clinicopathological characteristics of the tumor and can be used to identify a risk group for recurrence in primary resectable breast cancer.

A retrospective review of MRI features associated with metastasis-free survival in women with breast cancer: focusing on skin thickening and skin enhancement

OBJECTIVES

To identify associations between MRI-detected skin thickening and enhancement and metastasis-free survival (MFS) given recent reports of skin thickening on ultrasound being a poorer prognostic indicator.

METHODS

Interrogation of a prospectively collected database of ultrasound-visible breast lesions showed 214 lesions with pre-treatment MRIs available for analysis in a single centre. Data on MFS was prospectively collected. Retrospective MRI review was performed blinded to outcome. Imaging factors recorded were presence of skin thickening and enhancement, non-mass-enhancement (NME) and abnormal nodes, mass characteristics, perilesional oedema and background parenchymal enhancement. Statistical analysis used chi-squared test, Kaplan-Meier survival curves, the Log-rank test and receiver-operator characteristic (ROC) curves.

RESULTS

During a median follow-up period of 5.6 years, 21 (10%) of 212 patients developed distant metastases. Skin thickening [24 of 30 (80%) vs 169 of 184 (92%), p = 0.043] and skin enhancement [15 of 20 (75%) vs 178 of 194 (92%), p = 0.016] were associated with poorer MFS. Large index lesion size [p < 0.001, AUC 0.823], large sum of masses [p < 0.001, AUC 0.813], increasing total lesion extent including NME [p < 0.001, AUC 0.749] and abnormal axillary nodes [55 of 66 (83%) vs 138 of 148 (93%), p = 0.024] were also associated with poorer MFS.

CONCLUSIONS

Skin thickening and enhancement on breast MRI are associated with poorer MFS. These findings should be taken into account when managing patients with invasive breast cancer.

ADVANCES IN KNOWLEDGE

Skin enhancement on breast MRI at diagnosis is associated with metastases development. Skin thickening on breast MRI is associated with future metastatic disease.

Immunohistochemical evaluation of lymphovascular invasion in carcinoma breast with CD34 and D2-40 and its correlation with other prognostic markers

Background

Carcinoma breast is ever-evolving and becoming increasingly prevalent in India. Numerous prognostic factors based on morphology and immunohistochemistry (IHC) have been established which need to be interconnected to give patients best possible treatment.

Aims

This study aims to confirm and analyze lymphovascular invasion (LVI) detected by hematoxylin and eosin (H and E) using IHC with CD34 and D2-40 and its correlation with other biologic and morphologic prognostic markers.

Settings and Design

This was a prospective study.

Materials and Methods

Fifty mastectomy specimens diagnosed as infiltrating ductal carcinoma breast on histopathology selected for the study. Evaluation of formalin-fixed paraffin-embedded sections was done using H and E and IHC for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 HER2/neu receptors, CD34, and D2-40 endothelial markers. Correlation of LVI done with prognostic markers of Carcinoma Breast, namely, age of the patient, tumor size, Nottingham grade, lymph node ratio (LNR), Nottingham prognostic index (NPI), ER/PR status, and HER2/neu status. CD34 and D2-40 utilized to distinguish blood vessel, lymph vessel, and retraction artifacts and to calculate lymphatic microvessel density (LMVD) and blood microvessel density (BMVD).

Statistical Analysis Used

SPSS Software Package.

Results

LVI was associated with younger age (P = 0.001), greater tumor size (P = 0.007), higher Nottingham grade (P = 0.001), higher LNR (P = 0.001), higher NPI (P = 0.001), Negative ER Status (P = 0.001), Negative PR Status (P = 0.002), Positive HER2/neu status (P = 0.021), Higher Intratumoral BMVD (P = 0.016), Peritumoral BMVD (P = 0.001), and Intratumoral LMVD (P = 0.009). Blood vessels more commonly invaded than lymph vessels. Retraction artifacts can be mistaken for LVI without IHC.

Conclusions

D2-40 is a promising marker for lymphatic endothelium. LVI is a poor prognostic marker hence should be evaluated imperatively in all cases of carcinoma breast.

Prognostic Value of Lymphangiogenesis Determinants in Luminal and Non-luminal Breast Carcinomas

Background:

Breast carcinomas (BCs) are sub-classified according to the molecular characteristics into luminal and non-luminal subtypes that clinically show different biological behavior, treatment and prognosis. BCs spread primarily through lymphatic vessels using cascade processes of lymphagiogenesis in which VEGF-C plays an important role during lymph node metastasis. Prognostic value of VEGF-C in luminal and non-luminal BC is still unclear and has not been studied thoroughly to clarify and define prognosis and therapeutic monitoring.

Aim:

To define the prognostic value of lymphangiogenesis on survival rates of luminal and non-luminal subtypes BC.

Materials and Methods:

This study applied prospective cohort design, using 130 patients of invasive duct carcinoma of the breast, stage I-IIIA, from Sardjito General Hospital, Indonesia and subsequent longitudinal follow-up. Immunohistochemical staining was carried out using anti-ER, -PR, -Her-2, VEGF-C, VEGFR-3 and D2-40 antibodies. The related clinicopathologic characteristics of BC patients and lymphangiogenesis determinants, including VEGF-C expression, were statistically analyzed.

Results:

In non-luminal BC subtypes, VEGF-C expression (HR=0.04; 95% CI=0.01-0.41), lymph node metastasis (HR=0.14; 95% CI=0.04-0.55) and stage (HR=0.30; 95% CI= 0.02-0.76) were determined as independent prognostic factors on survival rates. However, the lymphangiogenesis determinants were not associated with the survival rates of luminal BC subtypes.

Conclusion:

This study suggested that lymphangiogenesis affects survival rates of non-Luminal subtype rather than the luminal subtypes of BC.

Clinical and Pathological Factors Affecting the Sentinel Lymph Node Metastasis in Patients with Breast Cancer

Sentinel lymph node biopsy has become the routine procedure in axilla-negative breast cancer patients at most medical centers for axillary staging and local control in the recent years. Sentinel lymph node is the only focus in axillary lymph metastasis in a large portion of patients. In our trial, we investigated the clinical and pathological factors that affect the positive status of sentinel lymph node. We included 89 patients, who underwent sentinel lymph node biopsy (SLNB) with methylene blue and/or technetium-99 m Sulphur Colloid due to early-stage breast cancer. Five patients, in whom SLN was not detected and who underwent axillary dissection, were excluded from the trial. The patient age, location of the tumor, the type of the tumor, the T stage by the TNM staging system, the histological grade and type of the tumor, the status of multifocality, the lymphovascular invasion status of the tumor, and the ER, PR, and HER-neu2 status were recorded. The median age of the 89 patients was 52, 9 (±10) years. Fifty-seven (64 %) and 32 (36 %) of the 89 patients were detected to have positive and negative SLN, respectively. Assessing the SLNB positivity and the patient age, tumor size, tumor grade, multifocality, tumor localization, the T stage by the TNM staging, the ER/PR positivity/negativity, and the HER/neu2 and p53 status, the data revealed no statistically significant results with respect to SLN metastasis. The lymphovascular invasion status (LVI) was observed to statistically affect the SLN positivity (p < 0.016). We showed that LVI could be an important marker in predicting the SLN positivity in patients with axilla-negative early-stage breast cancer. In the future, upon introduction of new biomarkers and with relevant studies, it may be possible to predict the SLNB status of patients at an adequately high accuracy and a low risk.

Prognostic significance of lymphatic invasion in lymph node-positive breast carcinoma: findings from a large case series with long-term follow-up using immunohistochemical endothelial marker

The poor prognostic significance of lymphatic invasion (LI) in breast carcinoma (BC) as a whole and in lymph node (LN)-negative patients in particular has been recognized in several studies; however, its prognostic role in LN-positive patients is still questionable. Aim of the current study was to assess prognostic role of LI in LN-positive BC specimens. Sections from non-selected 557 LN-positive BC specimens were stained with antibody to podoplanin/D2-40. LI was identified and correlated with clinicopathological features and patients' outcome. Twenty-year overall survival (OS), disease-free interval (DFI), and development of distant metastasis (DM) or recurrence were known for all patients. LI was detected in 262/557 (47%) of specimens ranging from 1 to 350 lesion per tumor section. Its presence was associated with higher grade tumors (P<0.0001), negative hormonal receptors (P<0.0001), high HER-2 expression (P=0.006), and with increased number of positive LNs (P=0.019). In the whole LN-positive BC, presence of LI was a poor prognostic factor for OS, DFI, and development of DM both in univariate and in multivariate analysis. In further stratification of patients, LI was associated with poorer prognosis in patients with single positive LN and not in patients with >1 positive LN. In T1N1 stage, LI was highly associated with poor OS (P=0.002), DFI (P<0.0001), and DM (P<0.0001). In T2N1 patients, LI was associated only with poorer DFI (P=0.037) but not with death or DM. In the two former patient groups, LI lost significance in multivariate analysis. In conclusion, LI is a poor prognostic factor in LN-positive BC particularly for patients having single positive LN. LI therefore would add further prognostic significance when considered in treatment in those patients. We recommend incorporation of LI in breast carcinoma staging and in prognostic indices.

Immunolocalization of glioma-associated oncogene homolog 1 in non melanoma skin cancer

Glioma-associated oncogene homolog (GLI)1 is involved in controlling cell proliferation and angiogenesis. The aim of this work was to explore its possible role in non-melanoma skin cancer pathogenesis through its immunohistochemical (IHC) expression in skin biopsies of these diseases and correlating this expression with the clinico-pathological parameters of the studied cases. Seventy-six cutaneous specimens were studied; 30 cases with basal cell carcinoma (BCC), 30 cases with squamous cell carcinoma (SCC) and 16 normal skin samples, from age- and gender-matched subjects, as a control group. GLI1 was expressed in all BCC cases and in 60% of SCC cases. All SCC cases showed cytoplasmic, while 70% of BCC cases showed nucleocytoplasmic immunoreactivity. It was over expressed in BCC and SCC compared to normal skin (p = 0.01 and 0.0006, respectively). Higher Histo (H) score in BCC cases was significantly associated with female gender (p = 0.04), multiple lesions, desmoplastic stromal reaction and stromal angiogenesis (p < 0.001 for all). Higher H score in SCC cases was significantly associated with scalp location, nodular type, recurrent lesions, high tumor grade, lymphovascular invasion (p = 0.004 for all), inflammatory stromal reaction (p = 0.01), lymph node involvement and absence of calcification (p = 0.001 for both). In conclusion, GLI1 may play a role in BCC pathogenesis through its role in cell proliferation, migration, and angiogenesis. Its upregulation and cytoplasmic localization in SCC may suggest that its role in tumor pathogenesis is through mechanisms other than Hedgehog pathway activation. Further studies are needed to clarify the exact molecular basis of its oncogenic action.

Podoplanin‑positive cancer cells at the edge of esophageal squamous cell carcinomas are involved in invasion

Podoplanin (PDPN) is a well established lymphatic endothelial marker and has frequently been observed in cancer cells at the edge of cancer masses. Previous studies investigating the association between PDPN expression and patient prognosis have had contradictory results. In the present study, it was hypothesized that the different locations of PDPN‑positive cells may explain these varying results. The present study aimed to focus on PDPN expression at the edge of esophageal cancer cell nests. In order to analyze the clinical significance of this PDPN expression, immunohistochemistry was performed using esophageal cancer tissue microarrays. PDPN expression at the edge of the cancer cell nest was found to be significantly associated with invasion (P<0.05) and poor prognosis (P<0.001) in patients with cancer. To further investigate the role of PDPN expression in cancer cells, the PDPN gene was cloned and transfected into esophageal squamous cell carcinoma (ESCC) cell lines. PDPN expression was also knocked down using small interfering RNA. PDPN‑positive cancer cells were found to exhibit invasion characteristics. Thus, PDPN expression at the edge of a cancer cell nest may indicate invasion and represent a poor prognostic factor for ESCCs.

Prediction of axillary lymph node metastases in breast cancer patients based on pathologic information of the primary tumor

BACKGROUND

Axillary lymph nodes (ALN) are the most commonly involved site of disease in breast cancer that has spread outside the primary lesion. Although sentinel node biopsy is a reliable way to manage ALN, there are still no good methods of predicting ALN status before surgery. Since morbidity in breast cancer surgery is predominantly related to ALN dissection, predictive models for lymph node involvement may provide a way to alert the surgeon in subgroups of patients.

MATERIAL AND METHODS

A total of 1325 invasive breast cancer patients were analyzed using tumor biological parameters that included age, tumor size, grade, estrogen receptor, progesterone receptor, lymphovascular invasion, and HER2, to test their ability to predict ALN involvement. A support vector machine (SVM) was used as a classification model. The SVM is a machine-learning system developed using statistical learning theories to classify data points into 2 classes. Notably, SVM models have been applied in bioinformatics.

RESULTS

The SVM model correctly predicted ALN metastases in 74.7% of patients using tumor biological parameters. The predictive ability of luminal A, luminal B, triple negative, and HER2 subtypes using subgroup analysis showed no difference, and this predictive performance was inferior, with only 60% accuracy.

CONCLUSIONS

With an SVM model based on clinical pathologic parameters obtained in the primary tumor, it is possible to predict ALN status in order to alert the surgeon about breast cancer counseling and in decision-making for ALN management.

Vascular invasion as an independent prognostic factor in lymph node negative invasive breast cancer

INTRODUCTION

Identification of simple and measurable prognostic factors is an important issue in treatment evaluation of breast cancer. The present study was conducted to evaluate the prognostic role of vascular invasion in lymph node negative breast cancer patients.

METHODS

in a retrospective design, we analyzed the recorded profiles of the 1,640 patients treated in the breast cancer department of Motahari clinic affiliated to Shiraz University of Medical Sciences, Shiraz, Iran, from January 1999 to December 2012. Overall and adjusted survivals were evaluated by the Cox proportional hazard model. All the hypotheses were considered two-sided and a p-value of 0.05 or less was considered as statistically significant.

RESULTS

Mean age in lymph node negative and positive patients was 50.0 and 49.8 respectively. In lymph node negative patients, the number of nodes, tumor size, lymphatic invasion, vascular invasion, progesterone receptor, and nuclear grade were significant predictors. In lymph node and lymphatic negative patients, vascular invasion also played a significant prognostic role in the survival which was not evident in lymph node negative patients with lymphatic invasion.

DISCUSSION

The results of our large cohort study, with long term follow up and using multivariate Cox proportional model and comparative design showed a significant prognostic role of vascular invasion in early breast cancer patients. Vascular invasion as an independent prognostic factor in lymph node negative invasive breast cancer.

Clinical significance of lymphatic and blood vessel invasion in oral tongue squamous cell carcinomas

Although vascular invasion (VI) is recognized as an important predictor of lymph node metastasis and a significant prognostic factor in head and neck squamous cell carcinoma (HNSCC), there is currently no common definition for the pathological evaluation of VI status. We reviewed the medical records of 63 consecutive resected primary oral tongue SCCs (OTSCCs) without preoperative treatment between June 1999 and April 2008, and evaluated VI status by investigating lymphatic vessel invasion (LVI) and blood vessel invasion (BVI) by using immunohistochemistry (IHC) with monoclonal antibody D2-40 (D2-40) and Elastica van Gieson (EVG) staining, respectively. Subsequently, we analyzed their correlations with cervical lymph node metastasis and prognosis. LVI was found in 16 of the 63 tumors (25.4%) and BVI was in 32 tumors (50.8%). Univariate analysis revealed that the presence of LVI is statistically correlated with lymph node metastasis. Moreover, multivariate logistic regression analysis revealed that LVI is an independent risk factor of nodal metastasis (odds ratio=4.262, 95% confidence interval=1.262-14.397, p=0.020). In contrast, Kaplan-Meier survival analysis revealed that patients with BVI had a significantly shorter disease-free survival (DFS) and overall survival (OS) rates than those without BVI (68.6% versus 90.3%, p=0.028 and 68.6% versus 93.5%, p=0.013, respectively). The present study clearly demonstrated that LVI at primary OTSCC had significant correlation with lymph node metastasis, and that BVI was significantly associated with recurrence and poor prognosis. Evaluation of VI status, as LVI and BVI status separately, using IHC with D2-40 and EVG staining may be useful in predicting lymph node metastasis and poor prognosis in OTSCCs.

Tumor characteristics influencing non-sentinel lymph node involvement in clinically node negative patients with breast cancer

PURPOSE

The negative sentinel lymph node (SLN) biopsy avoids conventional axillary dissection in patients with breast cancer with clinically negative axilla. Despite negative SLN, there is a risk of leaving involved non-SLN behind in the axilla. We investigated the predictive power of tumor characteristics for non-SLN metastasis.

METHODS

Lymphatic mapping with blue dye method for SLN biopsy and level 1-2 axillary dissections were performed to establish axillary status in 59 patients with T1 and T2 breast cancer and clinically negative axilla. Tumor's characteristics were histopathologically established to assess their association with non-SLN metastasis.

RESULTS

The axilla was malignant in 23 (39%) patients. The SLN alone was metastatic in 10, both SLN and non-SLN in 9, and non-SLN alone in 4 (7%) patients. The false negative rate for SLN biopsy was 10% in our series. The rate of positive non-SLN was found as 0% in T1a-b, 19% in T1c, and 40% in T2 tumors (p=0.035). Lymphovascular invasion was positive in 14 (61%) patients with axillary metastasis (p<0.001), and in 10 (77%) patients with non-SLN involvement (p<0.001).

CONCLUSION

We concluded that there was a small risk of involved non-SLN despite negative SLN. Tumor size (near or greater than 2 cm) was significantly associated with non-SLN metastasis. Peritumoral lymphovascular invasion was a positive predictor of the metastatic involvement in non-SLNs.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

Local relapse rates are falling after breast conserving surgery and systemic therapy for early breast cancer: can radiotherapy ever be safely withheld?

Rates of local tumour relapse after breast conservation treatment in women with early breast cancer are falling. Explanations for this decline are considered in this review including advances in breast cancer management and aging of the breast cancer population. Breast surgery has become more standardised following publication of practice guidelines and is mostly carried out by specialist surgeons. Systemic therapies (hormonal therapy and chemotherapy) are now more effective and are recommended to a higher proportion of patients than ever before. Radiotherapy techniques have also improved. The contributions of each factor are difficult to quantify precisely, but all are likely to be relevant. In order to identify a subgroup of women that might safely be spared radiotherapy, several factors are analysed, including the prognostic significance for local relapse of tumour characteristics (pathologic data, gene-expression profiles), patient characteristics and life expectancy (age and comorbidities).