Radiation and other pathological changes in breast tissue after conservation treatment for carcinoma

Biological effects of intraoperative radiation therapy: histopathological changes and immunomodulation in breast cancer patients

Introduction

Intraoperative radiation therapy (IORT) delivers a single accelerated radiation dose to the breast tumor bed during breast-conserving surgery (BCS). The synergistic biologic effects of simultaneous surgery and radiation remain unclear. This study explores the cellular and molecular changes induced by IORT in the tumor microenvironment and its impact on the immune response modulation.

Methods

Patients with hormone receptor (HR)-positive/HER2-negative, ductal carcinoma in situ (DCIS), or early-stage invasive breast carcinoma undergoing BCS with margin re-excision were included. Histopathological evaluation and RNA-sequencing in the re-excision tissue were compared between patients with IORT (n=11) vs. non-IORT (n=11).

Results

Squamous metaplasia with atypia was exclusively identified in IORT specimens (63.6%, p=0.004), mimicking DCIS. We then identified 1,662 differentially expressed genes (875 upregulated and 787 downregulated) between IORT and non-IORT samples. Gene ontology analyses showed that IORT was associated with the enrichment of several immune response pathways, such as inflammatory response, granulocyte activation, and T-cell activation (p<0.001). When only considering normal tissue from both cohorts, IORT was associated with intrinsic apoptotic signaling, response to gamma radiation, and positive regulation of programmed cell death (p<0.001). Using the xCell algorithm, we inferred a higher abundance of γδ T-cells, dendritic cells, and monocytes in the IORT samples.

Conclusion

IORT induces histological changes, including squamous metaplasia with atypia, and elicits molecular alterations associated with immune response and intrinsic apoptotic pathways. The increased abundance of immune-related components in breast tissue exposed to IORT suggests a potential shift towards active immunogenicity, particularly immune-desert tumors like HR-positive/HER2-negative breast cancer.

Breast percent density changes in digital mammography pre- and post-radiotherapy

INTRODUCTION

Breast cancer (BC), the most frequently diagnosed malignancy among women worldwide, presents a public health challenge and affects mortality rates. Breast-conserving therapy (BCT) is a common treatment, but the risk from residual disease necessitates radiotherapy. Digital mammography monitors treatment response by identifying post-operative and radiotherapy tissue alterations, but accurate assessment of mammographic density remains a challenge. This study used OpenBreast to measure percent density (PD), offering insights into changes in mammographic density before and after BCT with radiation therapy.

METHODS

This retrospective analysis included 92 female patients with BC who underwent BCT, chemotherapy, and radiotherapy, excluding those who received hormonal therapy or bilateral BCT. Percent/percentage density measurements were extracted using OpenBreast, an automated software that applies computational techniques to density analyses. Data were analysed at baseline, 3 months, and 15 months post-treatment using standardised mean difference (SMD) with Cohen's d, chi-square, and paired sample t-tests. The predictive power of PD changes for BC was measured based on the receiver operating characteristic (ROC) curve analysis.

RESULTS

The mean age was 53.2 years. There were no significant differences in PD between the periods. Standardised mean difference analysis revealed no significant changes in the SMD for PD before treatment compared with 3- and 15-months post-treatment. Although PD increased numerically after radiotherapy, ROC analysis revealed optimal sensitivity at 15 months post-treatment for detecting changes in breast density.

CONCLUSIONS

This study utilised an automated breast density segmentation tool to assess the changes in mammographic density before and after BC treatment. No significant differences in the density were observed during the short-term follow-up period. However, the results suggest that quantitative density assessment could be valuable for long-term monitoring of treatment effects. The study underscores the necessity for larger and longitudinal studies to accurately measure and validate the effectiveness of quantitative methods in clinical BC management.

Quantitative evaluation of radiation-induced metabolic changes in the ipsilateral breast by FDG-PET/CT

Background and aim

There are no reports of quantitative evaluation of metabolic changes in the mammary gland after radiation therapy. The purpose of this study was to investigate metabolic changes in the ipsilateral mammary gland after radiation therapy and to evaluate the late radiation effects.

Patients and methods

Metabolic changes of the ipsilateral and contralateral mammary glands were retrospectively evaluated by F-18 fluorodeoxyglucose (FDG) PET/CT after whole breast irradiation following lumpectomy in five breast cancer patients. The maximum standardized uptake values (SUVmax) of the ipsilateral mammary gland (S1) and the contralateral mammary gland (S0) were measured. The relative SUVmax (= S1/S0) was measured immediately before, one year after, three years after, and five years after radiation therapy.

Results

The SUVmax of the ipsilateral mammary gland decreased gradually, but there was no decrease in the SUVmax of the contralateral mammary gland. Relative SUVmax values before, 1, 3, and 5 years after radiation therapy were 1.33 ± 0.20, 1.13 ± 0.35, 0.99 ± 0.26 and 0.62 ± 0.10, respectively. Relative SUVmax value at 5 years was significantly lower than before radiation therapy (P < 0.01).

Conclusions

18F-FDG PET/CT may be useful in assessing mammary gland function and predict lactation disorders in advance.

Atypia in breast pathology: what pathologists need to know

Despite the importance of atypia in diagnosing and classifying breast lesions, the definition of atypia varies depending on the context, with a lack of consistent and objective criteria for assessment. Atypia in breast pathology may be cytonuclear and/or architectural with different applications and implications. Cytonuclear atypia is used to assist the distinction of various intraductal epithelial proliferative lesions including usual ductal hyperplasia (UDH) versus atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS), and to grade DCIS. In invasive carcinoma, nuclear atypia (i.e., nuclear pleomorphism) is a component of the histological grading system. Stromal cell cytonuclear atypia is one of the key features used to distinguish fibroadenoma from phyllodes tumour (PT) and to classify PT as benign, borderline or malignant. Similarly, cytonuclear atypia is used in the evaluation of myoepithelial cell alterations in the breast. Architectural atypia is used to differentiate flat epithelial atypia (FEA) from ADH or DCIS. In addition to the inherent subjectivity in the interpretation of atypia, which presents as a morphological continuum reflecting a biological spectrum, the lack of standardisation in defining atypia augments diagnostic discordance in breast pathology, with potential implications for patient management. Evidence to date suggests that the traditional criteria used to assess atypia may require modification in the era of digital pathology primary diagnosis. This review aims to provide a comprehensive review of atypia in breast pathology with reference to inconsistencies, challenges and limitations.

Pathology of IgG4-related sclerosing mastitis

Immunoglobulin G4-related sclerosing mastitis (IgG4-RM) is a recently recognised member of the IgG4-related disease (IgG4-RD) family, a multisystem fibroinflammatory condition that can affect any organ system. IgG4-RM is rare and predominantly occurs in middle-aged women. It may present with painless palpable mass and/or lymphadenopathy thereby mimicking breast cancer. Although there is an abundance of literature describing the clinicopathological characteristics of IgG4-RD in a variety of organs, data on IgG4-RM are limited due to its rarity. This review describes the manifestation of the disease in the breast based on reported cases, emphasising the clinicopathological features, pathophysiology, differential diagnosis, treatment and prognosis.

Outcomes of Immediate Implant-Based Mastectomy Reconstruction in Women with Previous Breast Radiotherapy

BACKGROUND

The objective of this study was to determine whether women with a history of radiation therapy before mastectomy experience a risk for postoperative complications and patient-reported outcomes similar to those of women undergoing postmastectomy radiation therapy in the setting of immediate implant reconstruction.

METHODS

The cohort included patients undergoing immediate implant reconstruction at 11 centers across North America. Women were categorized into three groups: prior breast conservation therapy, postmastectomy radiation therapy, and no radiation therapy. Mixed effect logistic regressions were used to analyze the effects of radiation therapy status on complication rates and patient-reported outcomes.

RESULTS

ONE THOUSAND FIVE HUNDRED NINETY-FOUR: patients were analyzed, including 84 women with prior breast conservation therapy, 329 women who underwent postmastectomy radiation therapy, and 1181 women with no history of radiation therapy. Compared with postmastectomy radiation therapy, breast conservation was associated with lower rates of all complications and major complications (OR, 0.65; 95 percent CI, 0.37 to 1.14; p = 0.13; and OR, 0.61; 95 percent CI, 0.33 to 1.13; p = 0.12). These differences were not statistically significant. Rates of reconstructive failure between the two cohorts were comparable. Before reconstruction, satisfaction with breasts was lowest for women with prior breast conservation therapy (p < 0.001). At 2 years postoperatively, satisfaction with breasts was lower for women with postmastectomy radiation therapy compared with breast conservation patients (p = 0.007).

CONCLUSIONS

Higher postoperative complication rates were observed in women exposed to radiation therapy regardless of timing. Although women with prior breast conservation experienced greater satisfaction with their breasts and fewer complications when compared to women undergoing postmastectomy radiation therapy, there was a similar risk for reconstruction failure.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

3D Printing Breast Tissue Models: A Review of Past Work and Directions for Future Work

Breast cancer often results in the removal of the breast, creating a need for replacement tissue. Tissue engineering offers the promise of generating such replacements by combining cells with biomaterial scaffolds and serves as an attractive potential alternative to current surgical repair methods. Such engineered tissues can also serve as important tools for drug screening and provide in vitro models for analysis. 3D bioprinting serves as an exciting technology with significant implications and applications in the field of tissue engineering. Here we review the work that has been undertaken in hopes of generating the recognized in-demand replacement breast tissue using different types of bioprinting. We then offer suggestions for future work needed to advance this field for both in vitro and in vivo applications.

Modern therapies and iatrogenic changes in breast pathology

Iatrogenic changes within the breast can provide challenges for the histopathologist in routine practice. Diagnostic procedures, such as core biopsies, result in reactive changes and can cause displacement of benign and malignant cells, the interpretation of which may cause difficulties in the resection specimen. Breast augmentation surgery with implants or injection of fillers, performed for cosmetic reasons or as part of a reconstructive process following removal of breast cancer, also produces reactive changes locally and at distant sites that may mimic cancer. The entity of implant-associated anaplastic large-cell lymphoma is now well recognized, with progress in our understanding of the underlying biological factors that drive its development. Chemotherapy and radiotherapy used in the treatment of breast cancer causes characteristic changes in normal breast tissue, and can alter the histological appearance and receptor status of the tumour. Radiotherapy to the breast, for breast cancer or childhood malignancies, increases the risk of developing a secondary malignancy in the breast long after treatment. In this review, we describe some of the iatrogenic changes that may be seen in histological specimens from the breast.

Exuberant Squamous Metaplasia with Calcification Following Intraoperative Radiotherapy for Breast Carcinoma: Report of an Unusual Case and Retrospective Review of Cases from a Single Institution

Intraoperative radiotherapy (IORT) is a novel and increasingly utilized radiation technique in the treatment of breast carcinoma. There are few reports on the histologic changes seen in breast tissue from patients who have undergone IORT. We sought to evaluate the histologic changes observed in specimens received following IORT, as well as report an unusual case which prompted our study. A retrospective review of patients who received IORT and subsequently had breast tissue histologically evaluated at our institution was performed. Fifteen post-IORT specimens from 12 patients, including the patient from the reported case, were studied. We report a case of a 77-year-old woman found to have mammographic microcalcifications at the lumpectomy site 6 months following lumpectomy and IORT for ductal carcinoma in situ (DCIS). A stereotactic biopsy showed abundant desquamated anucleate squamous cells with calcification and keratin material associated with squamous metaplasia of ducts. Carcinoma was not present. The predominant findings in the post-IORT specimens were fat necrosis and scar (n = 5), recurrent invasive carcinoma (n = 5), surgical site changes (n = 3), abscess (n = 1), and exuberant squamous metaplasia with calcification (n = 1). Five of fifteen (33%) post-IORT specimens showed squamous metaplasia, all of which were collected within 6 months of IORT delivery. The morphologic changes observed after IORT are similar to those seen after external beam radiotherapy. Exuberant squamous metaplasia is an uncommon consequence of IORT; however, pathologists should be aware of this phenomenon and review a history of prior intraoperative radiation before raising concern for malignancy.

Utility of immunohistochemical markers in irradiated breast tissue: an analysis of the role of myoepithelial markers, p53, and Ki-67

Radiation therapy is an important adjunct to breast-conserving surgery, but the diagnosis of recurrent/de novo carcinoma in a background of radiation atypia can be difficult, especially on small biopsies. Immunostaining for myoepithelial cell proteins is often used to assess invasion in nonirradiated breast tissue, yet these stains have not been investigated specifically in irradiated breast. We studied 29 irradiated breast resection specimens, some with carcinoma in situ (CIS, n=13) and/or invasive carcinoma (n=13). Representative blocks were stained for the myoepithelial proteins p63, smooth muscle myosin heavy chain (SMM), calponin, CK5/6, the proliferative marker Ki-67, and the tumor-suppressor p53. Nonirradiated control tissue was also stained with Ki-67 and p53 (CIS, normal, contralateral). Areas of radiation atypia/atrophy and nearly all CIS in irradiated breast tissue had abundant myoepithelial cells as evidenced by SMM, calponin, and p63 stains, with focal staining attenuation or gaps with SMM and calponin and frequently absent CK5/6 staining. As predicted, myoepithelial cell staining was absent in invasive carcinoma. p63 staining revealed postradiation myoepithelial nuclear morphologic changes. p53 staining was increased, although weak, in irradiated non-neoplastic breast (12% irradiated; 4% nonirradiated); however, irradiated CIS had less p53 staining when compared with control CIS (3% irradiated; 38% nonirradiated). As expected, Ki-67 was increased in carcinoma as compared with non-neoplastic irradiated tissue. Thus, myoepithelial immunostaining is a useful diagnostic adjunct in irradiated breast, with caveats similar to nonirradiated breast. Ki-67 may be helpful in some postradiation specimens; however, p53 staining is not reliable in this setting.

Breast irradiation and lactation: a review

The incidence of breast cancer in premenopausal women is increasing and many of them still remain fertile after treatment. Allied to the current tendency to postpone pregnancy, it is expected that an increasing number of patients undergoing conservative treatment for breast cancer will get pregnant. Anatomical and histopathological aspects and the probability of lactation and breast feeding after breast irradiation are reviewed in this article. Lactation is possible after radiotherapy, present in at least 50% of the patients, but in reduced volume. This perspective is more correlated to the type of surgery and radiation dose used. Biochemical changes were observed in irradiated breast milk. Breastfeeding in the contralateral breast is not affected.

Monomorphic epithelial proliferations of the breast: a possible precursor lesion associated with ipsilateral breast failure after breast conserving therapy in patients with negative lumpectomy margins

BACKGROUND

It is generally believed that ipsilateral breast failures (IBFs) after breast-conserving therapy (BCT) develop from incompletely eradicated carcinoma. We previously suggested that monomorphic epithelial proliferations (MEPs) in the breast may be a pool of partially transformed clones from which breast carcinomas can arise and that radiation therapy (RT) may also reduce the risk of IBF by eradicating MEPs. We examined salvage mastectomy specimens in patients experiencing an IBF to define the relationship between MEPs and IBFs and an additional potential mechanism for IBF risk reduction by RT.

METHODS AND MATERIALS

The location, number, and distribution of radiation changes and MEPs relative to 51 IBFs were mapped in salvage mastectomy specimens from BCT patients with adequately excised, initial carcinomas (negative lumpectomy margins).

RESULTS

All 51 salvage mastectomies had diffuse, late radiation changes. None had active fibrocystic lesions. MEPs were predominantly located in the immediate vicinity of the IBFs. A mean of 39% of MEP cases were located within the IBF, 46% were located within 2 cm of the IBF, and 14% were 2-3 cm from the IBF.

CONCLUSIONS

MEPs appear to be a pool of partially transformed precursor lesions that can give rise to ductal carcinoma in situ and invasive carcinomas (CAs). Many IBFs may arise from MEPs that reemerge after RT. Radiation may also reduce IBF risk after BCT (including in patients with negative margins) by primarily eradicating MEPs.

Nonneoplastic alterations of the mammary epithelium can mimic atypia

CONTEXT

The pathologist evaluating breast biopsy specimens sometimes encounters nonneoplastic alterations of the mammary epithelium that raise the differential diagnosis of atypia. Because the identification of atypical ductal hyperplasia of the breast has significant clinical implications, it is important to correctly recognize its nonneoplastic morphologic mimics.

OBJECTIVE

To highlight a spectrum of physiologic and treatment-related changes that can occur in the mammary epithelium and to discuss the differential diagnosis with true atypia.

DATA SOURCES

A comprehensive review of the published English literature on physiologic and treatment-related changes of the breast epithelium was performed.

CONCLUSIONS

Among physiologic alterations of the ductal epithelium, luteal-phase changes and secretory changes can sometimes be overinterpreted as atypical. Treatment-related changes, secondary to chemotherapy and radiation, can pose a major diagnostic challenge and their misinterpretation as neoplastic carries major clinical consequences. Familiarity with the morphology of both physiologic and treatment-related alterations of the mammary epithelium is essential to avoid misdiagnosis.

Papillary adenocarcinoma of the thymus: case report and review of the literature

A 44-year-old male with a mediastinal mass measuring 3.5 × 3.5 × 3 cm was diagnosed with papillary adenocarcinoma of the thymus. Other origins of papillary adenocarcinoma were excluded by clinical, imaging, and immunocytochemical methods before assuming this diagnosis. Residual thymus was seen under the microscope. Focal CD5 immunoreactivity was present. There was no associated thymoma. The patient underwent surgery, radiotherapy, and chemotherapy. He disclosed systemic recurrence at 18 months (subcutaneous nodule). He is alive after 24 months of follow-up with active disease. There had been only 7 cases of this rare entity published before.

Multidisciplinary Therapy of Locally Far‐Advanced or Inflammatory Breast Cancer with Fixed Perioperative Sequence of Epirubicin, Vinorelbine, and Fluorouracil Chemotherapy, Surgery, and Radiotherapy: Long‐Term Results

BACKGROUND

Based on phase II data in advanced breast cancer (BC), the fluorouracil, epirubicin, and vinorelbine (FEN) combination was assessed as perioperative chemotherapy, integrated in a multidisciplinary treatment for locally advanced BC.

PATIENTS AND METHODS

Patients with newly diagnosed inoperable (stage IIIB or inflammatory) BC. Multimodality treatment protocol consisted of four preoperative courses of fluorouracil (600 mg/m(2) day 1), epirubicin (75 mg/m(2) day 1), and vinorelbine (25 mg/m(2) day1 and day 8), all i.v. every 21 days, followed by radical or conservative surgery according to clinical response and four postoperative identical chemotherapy courses aimed to eradicate micrometastatic disease. Locoregional radiotherapy was offered to all patients after the completion of chemotherapy followed by hormonotherapy according to hormone receptor status. The primary end points of the study were: (a) clinical and pathological response, (b) downstaging and conversion to operable disease, and (c) recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Forty-eight women, one stage IIIA, 27 (56.2%) stage IIIB, two stage IIIC (4.1%), and 12 (25%) with inflammatory BC, aged 34-75 years (median, 52), were accrued. Thirty-eight and 34 patients completed the planned pre- and postoperative chemotherapy, respectively. Totals of 175 and 135 cycles were administered pre- and postoperatively, respectively. Toxicity of both phases, mainly hematologic, was in general acceptable without treatment-related death. Venous reactions were a frequent problem. All but three tumors were converted to operable, 31.3% with breast conservation. The clinical response rate (RR) was 77.7% (22.2% complete) and pathological RR was 73.3% (complete, 20% in both primary and axilla). After a median follow-up of 72 months, 62.5% and 16.7% of patients remain relapse free at 3 and 5 years, respectively, while 83% and 58.3% were alive 3 and 5 years, respectively, after the start of chemotherapy. Median RFS and OS have not yet been reached, and are currently 37+ and 62+ months, respectively.

CONCLUSION

This fixed number of FEN perioperative courses schedule followed by radiotherapy is safe and highly active in inducing both local and distant control of locally far-advanced BC. This strategy is at least not inferior to other established regimens or strategies for locally far-advanced BC, while the integration of taxanes or new targeted agents may help show its true value for this challenging clinical entity.

Radiation and the microenvironment - tumorigenesis and therapy

Radiation rapidly and persistently alters the soluble and insoluble components of the tissue microenvironment. This affects the cell phenotype, tissue composition and the physical interactions and signalling between cells. These alterations in the microenvironment can contribute to carcinogenesis and alter the tissue response to anticancer therapy. Examples of these responses and their implications are discussed with a view to therapeutic intervention.

Radiation-induced Histopathologic Changes of the Breast

The increasingly frequent use of radiation therapy (RT) and systemic chemotherapy (CT) in the treatment of breast carcinoma requires surgical pathologists and cytologists to be familiar with the variable histologic changes initiated by these agents. Both treatment modalities can cause severe epithelial abnormalities, which are difficult to distinguish from carcinoma. The progression or regression of these histologic abnormalities in nonneoplastic breast tissue have not been extensively evaluated. Our study used 120 post-RT biopsy or mastectomy specimens from 117 patients (3 had bilateral carcinoma treated with RT) yielding 120 specimens. The interval from post-RT to biopsy or mastectomy ranged from 1 to 229 months with 25 of the specimens obtained 1 to 12 months after cessation of RT and 95 more than a year post-RT. Twenty-seven specimens were from >6 years after RT. The histologic features of pretreatment and posttreatment specimens were graded (0-3) blindly for each histologic feature to include stromal vascular and fibroblastic changes and epithelial cell changes of the terminal duct lobular unit and extralobular ducts as well as terminal duct lobular unit fibrosis/atrophy. The changes between the pre- and post-RT grades were all statistically significant (P < 0.05) using multiple nonparametric statistical methods and the parametric Student t test. The specimens obtained within the first year post-RT were compared with those from >1 year post-RT, >3 years post-RT, and >6 years post-RT. None of the histologic features evaluated showed significant changes over the various time intervals regardless of the statistical method used. The absence of regression of the radiation-induced histologic changes over time mandates the surgical pathologist be alert to the possibility of RT or CT even without that therapeutic history.

Factors influencing cosmetic results after conservation therapy for breast cancer

PURPOSE

Host, tumor, and treatment-related factors influencing cosmetic outcome are analyzed for patients receiving breast conservation treatment.

METHODS AND MATERIALS

Four-hundred and fifty-eight patients with evaluable records for cosmesis evaluation, a subset of 701 patients treated for invasive breast cancer with conservation technique between 1969 and 1990, were prospectively analyzed. In 243 patients, cosmetic evaluation was not adequately recorded. Cosmesis evaluation was carried out from 3.7 months to 22.3 years, median of 4.4 years. By pathologic stage, tumors were 62% T1N0, 14% T1N1, 15%, T2N0, and 9% T2N1. The majority of patients were treated with 4-6 MV photons. Cosmetic evaluation was rated by both patient and physician every 4-6 months. A logistic regression analysis was completed using a stepwise logistic regression. P-values of 0.05 or less were considered significant. Excellent cosmetic scores were used in all statistical analyses unless otherwise specified.

RESULTS

At most recent follow-up, 87% of patients and 81% of physicians scored their cosmetic outcome as excellent or good. Eighty-two percent of physician and patient evaluations agreed with excellent-good vs. fair-poor rating categories. Analysis demonstrated a lower proportion of excellent cosmetic scores when related to patient age > 60 years (p = 0.001), postmenopausal status (p = 0.02), black race (p = 0.0034), and T2 tumor size (p = 0.05). Surgical factors of importance were: volume of resection > 100 cm3 (p = 0.0001), scar orientation compliance with the National Surgical Adjuvant Breast Project (NSABP) guidelines (p = 0.0034), and > 20 cm2 skin resected (p = 0.0452). Extent of axillary surgery did not significantly affect breast cosmesis. Radiation factors affecting cosmesis included treatment volume (tangential breast fields only vs. three or more fields) (p = 0.034), whole breast dose in excess of 50 Gy (p = 0.0243), and total dose to tumor site > 65 Gy (p = 0.06), as well as optimum dose distribution with compensating filters (p = 0.002). Daily fraction size of 1.8 Gy vs. 2.0 Gy, boost vs. no boost, type of boost (brachytherapy vs. electrons), total radiation dose, and use of bolus were not significant factors. Use of concomitant chemotherapy with irradiation impaired excellent cosmetic outcome (p = 0.02). Use of sequential chemotherapy or adjuvant tamoxifen did not appear to diminish excellent cosmetic outcomes (p = 0.31). Logistic regression for excellent cosmetic outcome analysis was completed for age, tumor size, menopausal status, race, type of surgery, volume of breast tissue resected, scar orientations, whole breast radiation dose, total radiation dose, number of radiation fields treated, and use of adjuvant chemotherapy. Significant independent factors for excellent cosmetic outcome were: volume of tissue resected (p = 0.0001), type of surgery (p = 0.0001), breast radiation dose (p = 0.005), race (p = 0.002), and age (p = 0.007).

CONCLUSIONS

Satisfactory cosmesis was recorded in 81% of patients. Impaired cosmetic results are more likely with improper orientation of tylectomy and axillary incisions, larger volume of breast resection, radiation dose to the entire breast in excess of 50.0 Gy, and concurrent administration of chemotherapy. Careful selection of treatment procedures for specific patients/tumors and refinement in surgical/irradiation techniques will enhance the cosmetic results in breast conservation therapy.