T3b-T4 breast cancer: factors affecting results in combined modality treatments

EXPRESSION OF ALU REPEAT IN BLOOD PLASMA OF PATIENTS WITH BREAST CANCER DURING NEOADJUVANT CHEMOTHERAPY: AN EXPLORATORY STUDY

BACKGROUND

Locally advanced breast cancer (LABC) rates are unusually high in developing countries. There is a need for the identification of predictive biomarkers for the selection of patients who could benefit from neoadjuvant chemotherapy (NAC).

AIM

As the expression of ALU repeat is increased in cancer and has not been assessed in liquid biopsy of cancer patients, our goal was to assess ALU expression in the blood plasma of LABC patients during NAC.

PATIENTS AND METHODS

Plasma samples drawn at baseline and at the end of the fourth cycle of chemotherapy were used to determine the plasma levels of ALU-RNA by quantitative real-time PCR.

RESULTS

ALU expression from baseline to the fourth cycle of NAC increased from a median relative level of 1870 to 3370 in the whole group (p = 0.03). The increase in ALU-RNA levels in the course of NAC was more pronounced in premenopausal women and in patients with hormone-positive tumors. In patients with complete response to NAC, baseline ALU expression was higher than that in those with partial response.

CONCLUSION

This exploratory study provides evidence that plasma ALU-RNA levels are modulated by the menopausal status and hormone receptor status of breast cancer patients and pre-therapeutic ALU-RNA levels might be useful in predicting the response to chemotherapy in a neoadjuvant setting.

Prospective Evaluation of Response Outcomes of Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Introduction Breast cancer is a global health problem, with more than 1 million cases of breast cancer diagnosed worldwide each year, and is the most common cancer among Indian women. Locally advanced breast cancer (LABC) accounts for 10-20% in the Western world while in India it accounts for 40-50% of all cases. Locally advanced breast cancer is a very common clinical scenario especially in developing countries possibly due to various factors like lack of education and poor socioeconomic status. Women with the locally advanced disease require multimodality therapy and coordinated treatment planning. This study aimed to prospectively study the clinical profile of the LABC patients presenting to our institute and also to evaluate the role of neoadjuvant chemotherapy in downstaging the tumor. Materials and Methods Seventy patients diagnosed with locally advanced breast cancer were enrolled in this prospective study. After thorough preoperative workup, patients were either taken up for upfront surgery or neoadjuvant chemotherapy followed by surgery. Post chemotherapy clinical response of the tumor and postoperative histopathological evaluation of the specimen was performed. Results The mean age of the patients in our study was 45 years. Out of 70 patients, 18 underwent upfront surgery, and 52 received neoadjuvant chemotherapy followed by surgery. A total of 44 cases had a clinical response to chemotherapy with 9% having a complete response. The incidence of margin positivity in the postoperative specimen was significantly lower in patients who received neoadjuvant chemotherapy. Conclusion  Locally advanced breast cancer accounted for the predominant number of breast cancer patients mostly females in their middle age. Neoadjuvant chemotherapy was effective in downstaging the tumor in the majority of cases, although complete clinical response was lower in our study. The rate of margin positivity in mastectomy specimens can also be reduced if chemotherapy is considered prior to mastectomy.

Locally Advanced Breast Cancer: Treatment Patterns and Predictors of Survival in a Saudi Tertiary Center

Background  Breast cancer (BC) is the most common cancer in the Kingdom of Saudi Arabia (KSA) and the second leading cause of cancer-related mortality. About 40% of BC in KSA is locally advanced BC (LABC), which has been associated with poorer survival compared with early diagnosed BC. Objective To review the presentation and outcomes of LABC, including the characteristics of the disease, different treatment modalities, overall survival (OS), disease-free survival (DFS), and local recurrence in relation to different radiotherapy (RT) techniques. Methods  We retrospectively reviewed the medical records of 153 female patients with pathologically proven LABC diagnosed at King Abdulaziz University Hospital, Jeddah, KSA, between 2009 and 2017. We obtained data on patient demographics, stage of cancer at diagnosis, tumor characteristics (subtype and receptor status), type of surgery, systemic treatments received (hormonal, targeted therapy, and chemotherapy), RT variables, and recurrence and death dates. Data were analyzed to assess OS and DFS by using Kaplan-Meier analyses and the log-rank test. Univariate and multivariate Cox proportional hazard regression analyses were used to explore and identify factors associated with survival. Results  The median survival time in the study population was 9.16 years. Older age (65+ years) was associated with worse OS and DFS than was younger age (<65 years) (hazard ratio (HR) 3.20, 95% CI 1.48-6.90, P = 0.003 and HR 2.21, 95% CI 1.12-4.36, P = 0.022, respectively). Regarding the type of surgery, having a mastectomy was associated with worse OS and DFS than was having a lumpectomy (HR 2.44, 95% CI 0.97-6.12, P = 0.05 and HR 2.41, 95% CI 1.13-5.14, P = 0.023, respectively). Positive estrogen and progesterone receptor status was associated with better OS and DFS than was a negative estrogen or progesterone receptor status (HR 0.13, 95% CI 0.05-0.30, P < 0.001 and HR 0.21, 95% CI 0.11-0.41, P < 0.001, respectively). Patients who received RT had a lower risk of recurrence than did those who did not receive RT (P = 0.011). Moreover, three-dimensional conformal RT was associated with lower local recurrence than intensity-modulated RT or volumetric-modulated arc therapy (P = 0.003). Conclusion  Multiple factors can affect the OS and DFS in LABC. Younger patients, having hormone-positive disease, and undergoing lumpectomy were associated with better outcomes. Adjuvant RT may improve local control and the use of three-dimensional conformal RT was superior for local control. Prospective studies with larger sample sizes are needed to further highlight these findings and to assess the role of chemotherapy and targeted therapy in patients with LABC.

BIK and GRP78 protein expression as possible markers of response to preoperative chemotherapy and survival in breast cancer

OBJECTIVE

BIK and GRP78 have shown differential expression profiles in breast cancer (BC) tissue, in addition to its important participation in the pathophysiology of cancer. The purpose of this study was to evaluate the association of BIK and GRP78 protein expression with clinical and pathologic response to preoperative chemotherapy, recurrence, disease-free survival (DFS) and overall survival (OS), in patients with BC.

MATERIAL AND METHODS

Fifty-three patients who received preoperative chemotherapy where included in an observational, analytical and retrospective study to assess the BIK and GRP78 protein expression by immunohistochemistry in microarrays of BC tissue obtained before treatment. Associations between BIK and GRP78 expression with clinicopathological characteristics, clinical and pathologic response to preoperative chemotherapy, and recurrence were analyzed using Chi-square or Fisher's exact test. OS and postoperative DFS were assessed at 5-year follow-up by Kaplan-Meir curves, and the difference according to BIK and GRP78 expression was evaluated using the log-rank test. Bivariate analysis was performed using Cox risk proportion model. A p value < 0.05 was considered to be statistically significant.

RESULTS

BIK and GRP78 staining revealed positive expression in 37 (71.2%) and 35 patients (72.9%) respectively. Association between pathological complete response (pCR) and positive expression of BIK (p = 0.046), as well as between clinical complete response (cCR) and negative expression of GRP78 was observed (p = 0.048). Patients with expression of GRP78 had lower DFS (HR = 3.46; 95% CI 1.01-11.80; p = 0.047) and shorter OS (HR = 3.49; 95% CI 1.04 a 11.72; p = 0.043).

CONCLUSION

When finding association of GRP78 and BIK protein expression with the response (clinical and pathologic respectively) to preoperative chemotherapy, and GRP78 with DFS and OS, in patients with BC, our results suggest a potential prognostic value of both proteins; however, a larger sample size is required to confirm this.

A Study on Clinical and Pathological Responses to Neoadjuvant Chemotherapy in Breast Carcinoma

Aim and objectives

To assess the effectiveness of neo-adjuvant chemotherapy and its impact on the clinical and pathological response in locally advanced breast cancer. To compare molecular subtypes of breast cancer with response to neo-adjuvant chemotherapy.

Patients and methods

This was a prospective study on patients who received neoadjuvant chemotherapy for breast carcinoma for a 3-year period. A total of 60 patients who presented with locally advanced breast cancer (LABC) were treated with neoadjuvant chemotherapy. Forty patients were treated with the 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) schedule, 16 patients were treated with Adriamycin and cyclophosphamide (AC), and four patients were treated with oral cyclophosphamide, intravenous methotrexate, and fluorouracil (CMF). Taxol was added in all node-positive cases, triple negative breast cancer (TNBC), and Her 2 positive cases. The clinical response was assessed with RECIST criteria after neoadjuvant chemotherapy. The response was compared with molecular subtypes of carcinoma breast and receptor status individually.

Results

A total of 60 female patients receiving primary chemotherapy for locally advanced breast malignancy were studied. The median age of the patients at the time of diagnosis was 44 years (range=24–73). In terms of menopausal status, 25 (42%) patients were pre-menopausal and 35 (58%) patients were post-menopausal. Histological classification showed invasive ductal carcinoma in 72% of patients, invasive lobular carcinoma in 15% of patients, and other types including mixed patterns in 13% of patients. Among 60 patients, 16 patients (26.6%) had clinically complete remission (cCR), 30 patients (50%) had partial remission, eight patients (13.3%) had stable disease, and six patients (10%) had progressive disease. Following neoadjuvant chemotherapy, 46 (76.6%) patient underwent Modified radical mastectomy surgery. Target therapy was given for Her2 neu patients after surgery. Hormonal therapy was added to hormone ER PR positive cases postoperatively. Eight patients (13.3%) among this operated cases attained complete pathological response.

Conclusion

Preoperative chemotherapy downstages the primary tumors and axillary metastasis in patients with locally advanced breast carcinoma. Comparison of molecular subtypes with chemotherapy response is a better way to find out the predictors of response to chemotherapy.

Inflammatory Component: A Worsening Factor in Locally Advanced Breast Cancer Treated by Radiotherapy and Systemic Therapy

Locally advanced and inflammatory carcinomas of the breast are two distinct entities with clear differential clinical criteria. We described a particular type of locally advanced breast cancer which, during its evolution, developed inflammatory characteristics limited to a small area of the skin. It, therefore, did not meet the common diagnostic criteria of inflammatory carcinoma. In our series, studied from December 1977 to January 1987, we treated 59 cases of locally advanced breast cancer and 105 cases of locally advanced breast cancer with an inflammatory component. The actuarial overall survival was 53.3 % at 5 years and 38.4 % at 7 years. Differences were observed when the two tumor types were compared. Specifically, locally advanced breast cancer with an inflammatory component had a worse prognosis, poorer survival and poorer disease-free rates than locally advanced breast cancer.

Definition and consequences of locally advanced breast cancer

PURPOSE OF REVIEW

Locally advanced breast cancer (LABC) represents the most advanced stage breast cancer that is still potentially curable with surgery, radiation, and systemic therapy. The purpose of this review is to discuss LABC in the context of modern practice with a focus on its definition and potential consequences.

RECENT FINDINGS

There is no one encompassing definition for this disease, but in general cancers of the breast are considered to be locally advanced if they are large and/or have infiltrated into adjacent tissues (the overlying skin or underlying muscles) and/or are found to have extensive locoregional lymph node involvement. It is not surprising, therefore, that LABC can cause significant morbidity and mortality.

SUMMARY

Recent advances in our understanding of the biology of breast cancer have made it clear that LABC does not represent a single clinical entity but rather a heterogeneous group of breast tumors that share a common theme of extensive locoregional spread without overt evidence of distant metastatic disease. Despite advances in breast cancer screening and treatment LABC remains a significant global healthcare issue.

A new approach in breast cancer with non-inflammatory skin involvement

The widely accepted image of breast cancer with non-inflammatory skin involvement (T4b) is determined by the tenet that all these tumors are locally advanced (Stage IIIB). The study addresses the question whether this view is justified. Data from 453 non-metastatic breast cancer patients were collected retrospectively. Eighty-one patients had T4b disease. To assess the malignant potential of tumors independent of the feature skin involvement, a reclassification only considering tumor size was undertaken. We compared the clinical course of three study groups (A: Stage II; B: Stage IIIA; C: Stage IIIC) with control groups of 372 patients without skin involvement. In the study groups, we found a broad distribution among the stages (A:36.2%; B:33.7%; and C:27.7%) with significant differences in disease-specific survival (DSS) (A/B: p = 0.032; B/C: p = 0.048). There were no significant differences in DSS between the study and the corresponding control group. In multivariate analysis, skin involvement was not a significant predictor of DSS. Heterogeneity of the T4b category and a lack of prognostic significance expand the widely accepted image of breast cancer with non-inflammatory skin involvement. The highest T category, or Stage III, is not the appropriate classification for a considerable number of patients having this clinicopathologic entity.

Management of patients with locally advanced breast cancer

The indications and benefits of postmastectomy radiation therapy (PMRT) continue to evolve. Advances in systemic adjuvant therapy and targeted therapy for breast cancer are likely to play an increasingly important role in control of locoregional as well as distant disease. Ongoing scrutiny of patterns of chest wall failure will be required to define the net benefit derived from PMRT. This article discusses the 2001 American Society of Clinical Oncology guidelines for PMRT and current practices using PMRT in selected groups of patients who have breast cancer.

Correlation and significance of histopathological and clinical features in breast cancer with skin involvement (T4b)

A retrospective review was performed to investigate the prognostic significance and validity of the pathological and clinical TNM staging of noninflammatory skin involvement in breast cancer. In 128 tumors with histologically proven skin involvement and a size up to 5 cm (64% of the entire group), we distinguished clearly between group A) cases showing the classical clinical signs (cT4b) and those that do not, and between group B) carcinomas infiltrating the epidermis (pT4b) and those infiltrating only the dermis. We found only moderate concordance (kappa = 0.44) between the pathological and clinical TNM staging system. In the analysis of 80 patients with a tumor size from 2.1 to 5.0 cm, neither the appearance of classical clinical signs nor the histological diagnosis of infiltration of the epidermis was shown to be a relevant factor. In comparison to the control groups, similar clinicopathologic entities without significant differences in long-term outcome were observed. After regrouping of the patients having tumor infiltration of the papillary dermis from the control group into the study group (pT4), the study group showed a significant higher number of involved axillary lymph nodes (P = .014) and a more extensive lymph node involvement (pN3; P = .025). The combination epidermis-papillary dermis seems to be more a functional unit than the epidermis alone that is defined as the crucial and delineating factor in the TNM Classification. Our results challenge the validity of the TNM rules and recommendations concerning T4b breast cancer because it leads, in the majority of cases, to tumors of comparable extent and prognosis being placed in different categories.

Scope and significance of non-uniform classification practices in breast cancer with non-inflammatory skin involvement: a clinicopathologic study and an international survey

BACKGROUND

The study evaluates the scope of non-uniform classification practices concerning breast carcinomas with non-inflammatory skin involvement.

PATIENTS AND METHODS

We compared the clinical course of patients with histologically proven non-inflammatory skin involvement: 119 (65.4%) with clinically obvious 'classical' skin changes (Group A) and 63 (34.6%) with no or only discreet changes (Group B). A questionnaire was circulated to pathology departments in 24 countries to assess the practice concerning the placement of skin- involved breast carcinomas in the TNM classification.

RESULTS

Patients in Group B showed a significantly better disease specific survival (P=0.0002). Eighty-six respondents (70.5%) of the survey preferred the 'histological view' and classified tumors with only histological proven skin involvement as T 4 b/stage IIIB. The opposing classification principle ('clinical view'), which dictates that T 4 b breast cancer is a clinical diagnosis and the classical signs must be present, was supported by 31 respondents (25.4%).

CONCLUSIONS

A large number of breast cancer patients with non-inflammatory skin involvement are only histologically proven and show, compared with cases exhibiting the classical clinical signs, significant differences in clinical course and prognosis. In general, both subsets were aggregated in one T category/stage (T 4 b/IIIB). This results in a considerable distortion of the reported statistical data.

Determinants of prognosis in breast cancer patients with tumor involvement of the skin (pT4b)

Determinants of prognosis were studied in patients with breast cancer with histologically proven tumor extension to the skin without clinical evidence of distant metastases (i.e., pT4b N0-3 M0). Data were collected retrospectively on 77 consecutive patients diagnosed in one community teaching hospital over the period from 1980 to 1995. The prognostic factor of tumor size showed a 5-year survival rate for patients with a tumor </=3 cm of 81% compared to 45% for patients with tumors larger than 3 cm (p = 0.002). Achievement of complete remission resulted in a 5-year survival rate of 66%, compared to 27% when complete remission was not achieved (p = 0.005). Another important prognostic factor was the development of local-regional recurrence: the 5-year survival rates for patients with and without local-regional recurrence were 39% and 87%, respectively (p < 0.001). Development of local-regional recurrence was also significantly related to tumor size (p = 0.02). Pathologic tumor size and the achievement of complete remission and local-regional control appear to be the most important prognostic factors for survival in patients with pT4b breast cancer without distant metastases. We conclude that the finding of a pT4b breast cancer does not always imply a dismal prognosis, especially for those patients with a tumor </=3 cm. A favorable prognosis can be expected when treatment is effective in achieving complete remission and in preventing the development of local-regional recurrence.

Update on locally advanced breast cancer

Locally advanced breast cancer remains a clinical challenge as the majority of patients with this diagnosis develop distant metastases despite appropriate therapy. Patients with locally advanced disease encompass a wide range of clinical scenarios including advanced primary tumors (stage T4), advanced nodal disease (fixed axillary nodes or involvement of ipsilateral supraclavicular, infraclavicular, or internal mammary nodes), and inflammatory carcinomas. The prognoses of women with locally advanced breast tumors are also heterogeneous and depend on tumor size, extent of lymph node involvement, and the presence or absence of inflammatory carcinoma. Women with locally advanced disease require multimodal therapy, and coordinated treatment planning among the medical oncologist, surgical oncologist, and radiation oncologist is necessary to optimize patient care. In this article, the epidemiology, evaluation, prognostic factors, and treatment for locally advanced breast cancer are discussed. Inflammatory cancer is also reviewed, but is considered separately due to its distinct biology and clinical behavior.

Long-term outcome of neoadjuvant therapy for locally advanced breast carcinoma: effective clinical downstaging allows breast preservation and predicts outstanding local control and survival

OBJECTIVE

To review the long-term follow-up data from the authors' institutional experience of 62 patients with locally advanced breast cancer (LABC) treated with a uniform multimodality regimen. The authors determined the rate of breast preservation, the disease-free and overall survival, and the factors associated with locoregional and distant recurrent disease.

SUMMARY BACKGROUND DATA

It remains a challenge to achieve local and distant control of LABC. Over the last decade, preoperative or neoadjuvant chemotherapy has emerged as the standard of care for these patients. Successful tumor downstaging has been associated with increased rates of breast-conserving therapy (BCT), but the overall effect on long-term survival remains to be seen.

METHODS

This study examines a cohort of 62 patients with LABC treated at the authors' institution from 1992 to 1998. The uniform treatment regimen consisted of neoadjuvant doxorubicin (Adriamycin), followed by operation (BCT if sufficient clinical downstaging), followed by non-cross-resistant cyclophosphamide/methotrexate/5-fluorouracil, followed by radiation therapy. Treatment was both dose-intensive and time-intensive, with a total treatment time of 32 to 35 weeks.

RESULTS

In this patient population, the median age was 44 years, with approximately two thirds white patients and one third African American. Eighty-two percent of patients were clinical stage III at presentation, 13 patients had T4d inflammatory cancers, and 3 patients were stage IV at diagnosis. Eighty-four percent of patients demonstrated a significant clinical response to doxorubicin. Twenty-eight patients had sufficient clinical downstaging to attempt BCT, and 22 (45%) of 49 noninflammatory patients underwent successful BCT. Pathologic complete response was seen in 15% of patients. Median follow-up for the cohort was 70 months. The local recurrence rate was 14%, including two ipsilateral breast tumor recurrences (10%) in the BCT patients. Seven (12%) patients developed a new primary cancer in the contralateral breast. Distant metastases occurred in 18 (31%) patients, and the 5-year overall survival rate for the cohort was 76%. Furthermore, in the patients who underwent an attempt at BCT, the survival rate was 96% at 5 years.

CONCLUSIONS

Dose-intensive and time-intensive multimodality neoadjuvant therapy was successfully administered to a mixed racial group over shortened times. Patients who had sufficient clinical downstaging to allow BCT have the best long-term outcome. Patients who required mastectomy are at a higher risk of relapse, as well as the development of new contralateral cancers, yet have 5-year survival rates of over 50%.

Multidisciplinary Management of Locally Advanced Breast Cancer

The treatment of locally advanced breast cancer is aimed at achieving long-term local control with local surgery and/or radiation therapy and at improving disease-free and overall survival through the application of systemic cytotoxic chemotherapy and hormonal therapy. Studies of local therapy alone with surgery or radiotherapy have demonstrated high rates of local recurrence and low rates of long-term survival. The application of anthracycline-based neoadjuvant chemotherapy has resulted in rates of response ranging from 72% to 97%, clinical complete responses of 12-52%, and pathologic complete responses of 4-33%. Multidisciplinary treatment with neoadjuvant therapy, followed by local surgery and/or radiation therapy, followed by additional chemotherapy, has resulted in rates of local control that exceed 80%, and 5-year survival rates exceeding 50% are not unusual. The use of anthracycline-based neoadjuvant chemotherapy in the treatment of locally advanced breast cancer is thus now firmly established. Research in the treatment of locally advanced breast cancer is needed to further define the optimal method of local therapy and the role of new agents such as the taxanes.

Breast cancer screening, diagnosis, and treatment

The incidence of breast cancer in US women remains disturbingly high, and unfortunately primary care physicians still frequently encounter patients in whom the disease is suspected or, even worse, confirmed. Fortunately, however, the body of knowledge surrounding the disease has grown dramatically during the past decade, and major advances have been made in the understanding of breast cancer risk, prevention, diagnosis, and treatment. Controversies persist, particularly those concerning the screening of younger women, but consensus now exists regarding many clinical issues relevant to primary care practice. Although multidisciplinary subspecialty expertise must be made available to all women with known or suspected breast cancer, the primary care physician has an important role to play when dealing with patients with this condition. The following article focuses on what primary care practitioners need to know to expertly contribute to the diagnosis, counseling, and initial treatment of women with this disease.

Combined sequential approach in locally advanced breast cancer

BACKGROUND

The interaction between primary and adjuvant chemotherapy is a crucial point in the treatment of locally advanced breast cancer.

OBJECTIVE

To evaluate the therapeutic efficacy of a sequential treatment with primary anthracyclines and adjuvant CMF in this patient subset.

DESIGN

Prospective cohort study.

PATIENTS

Eighty-eight breast cancer patients, stage T3b-T4 abc, N0-2, M0.

RESULTS

From February 1991 to July 1994, 88 consecutive patients with locally advanced breast cancer were treated at the Istituto Nazionale Tumori, Milano, with full-dose doxorubicin (75 mg/m2) or epirubicin (120 mg/m2) for three cycles followed by surgery, adjuvant chemotherapy with i.v. CMF for six cycles and local radiotherapy +/- Tamoxifen. A high rate of objective responses (70%), but a low incidence of pathologic complete remission (2%), were observed following primary treatment with single-agent anthracyclines. Frequency of responses was not associated with tumor estrogen or progesterone receptors status, Mib-1 or grading. In 28 patients (32%) conservative surgery could be performed. At a median follow-up of 52 months, relapse free survival and overall survival are 52% and 62%, respectively. A multivariate analysis demonstrated a significant favorable prognosis in patients with limited nodal involvement at surgery and negative Mib-1 values. This drug sequence failed to significantly ameliorate the long term results in this unfavorable patient subset and more effective drug regimens and innovative therapeutic strategies are needed.

The importance of postoperative radiation therapy in multimodality management of locally advanced breast cancer: a phase II trial of neoadjuvant MVAC, surgery, and radiation

PURPOSE

To determine the impact of postoperative radiation on locoregional relapse and overall survival rate in a multimodality protocol for locally advanced breast cancer (LABC).

MATERIAL AND METHODS

Of the patients entered in the protocol, 55 were evaluable. Treatment consisted of: neoadjuvant MVAC (methotrexate, vinblastine, adriamycin, and cisplatin) until a maximum response had been achieved; modified radical mastectomy; 6 courses of postoperative adjuvant MVAC chemotherapy, and chest wall irradiation (CWXRT). Multivariate analysis of locoregional response and overall survival was done.

RESULTS

Of the total, 42 patients received chest wall radiation; 28 of these also received radiation to regional lymph nodes. Chest wall doses ranged from 45 Gy to 50.4 Gy to the whole chest wall, with 31 patients receiving an additional chest-wall boost. The incidence of locoregional relapse with and without radiation was 7% vs. 31%, respectively (p = 0.026). An overall survival benefit was seen in those receiving radiation, with a mean overall survival of 50 months vs. 20 months, and a 3-year overall survival of 88% vs. 46% with and without radiation, respectively (p = 0.003). Multivariate analysis showed that overall survival was affected by the presence of pathological CR (p = .047), the number of pre-operative chemotherapy cycles (p = .036) and whether or not they received radiation (p = 0.003). Neither the interval between surgery and radiation, technique of radiation, nor radiation modality significantly affected local control.

CONCLUSION

The significant improvement in local regional control and overall survival with the addition of radiation suggests that radiation should be an integral part of multimodality management of locally advanced breast cancer.

A pilot evaluation of alternating preoperative chemotherapy in the management of patients with locoregionally advanced breast carcinoma

BACKGROUND

This prospective trial was conducted to evaluate the outcome of patients treated with preoperative and post operative chemotherapy, mastectomy, and irradiation for locoregionally advanced breast carcinoma.

METHODS

Between June 1986 and September 1990, 71 patients received 2 cycles of doxorubicin that alternated with 2 cycles of cyclophosphamide, methotrexate, and 5-fluorouracil prior to mastectomy; irradiation was administered when the tumor was not amenable to surgical resection. Additional chemotherapy and tamoxifen, in hormone receptor-positive tumors, was used after mastectomy. Post-operative irradiation was given on a selective basis for patients at high risk for locoregional disease recurrence.

RESULTS

Although 5 patients (7%) had disease progression, clinical partial or complete tumor response to preoperative chemotherapy was noted in 46 patients (65%). Sixty-eight patients (96%) underwent mastectomy. With a median follow-up of 52 months, the relapse-free and overall survival rates at 5 years were 42% and 57% respectively. Locoregional tumor recurrence occurred in 14 patients (20%), and 28 patients (39%) developed metastatic disease. Menopausal status, clinical presentation (noninflammatory vs. inflammatory), and American Joint Committee on Cancer clinical stage were independent covariates associated with patient outcome.

CONCLUSIONS

Preoperative alternating chemotherapy, with the selective use of irradiation, resulted in significant locoregional disease regression and the successful integration of mastectomy into the therapeutic strategy. Locoregional tumor control and relapse-free and overall survival estimates for the approach described herein compared favorably with other comtemporary reports for this condition.

Efficacy of up-front 5-fluorouracil-epidoxorubicin-cyclophosphamide (FEC) chemotherapy with an increased dose of epidoxorubicin in high-risk breast cancer patients

The prognosis of patients with stage IIIB breast carcinoma with tumour spread to the apical axillary lymph nodes has hardly improved despite adequate locoregional control and the introduction of systemic adjuvant therapy. A combined modality regimen that includes anthracyclin-based chemotherapy, high-dose chemotherapy with peripheral stem cell support and radiation and hormonal therapy is currently under investigation in this subset of patients. The present study aims to document the efficacy and feasibility of dose-intensive epidoxorubicin in combination with a standard dose of 5-fluorouracil and cyclophosphamide as up-front chemotherapy in this setting. A preoperative chemotherapy regimen consisting of three courses of 5-fluorouracil 500 mg m-2, epidoxorubicin 120 mg m-2 and cyclophosphamide 500 mg m-2 (FE120C) was administered at 21 day intervals without haematopoietic growth factors to 70 patients with apex node-positive disease. All patients were below 60 years of age and had not had prior chemotherapy or radiotherapy. Sixty-six patients were evaluable for clinical response and histopathological examination could be performed in 62 of these. Thirteen patients achieved a clinical complete response (20%). Of these patients, microscopic examination of the mastectomy specimen revealed absence of malignant cells in two and exclusively ductal carcinoma in situ (DCIS) in another two patients. In addition, of the 46 patients (70%) with a clinical partial response, at pathological examination one patient had sclerosis only and four had DCIS. This results in a pathological complete response in three (5%) of all patients and absence of invasive carcinoma in 10%. None of the patients progressed during chemotherapy. The major toxicity was moderate bone marrow suppression with a median white blood count (WBC) nadir of 1800 microliters-1 (range 500-4900). Other toxicities were mild. The full planned dose could be given without delays in 66 of 70 patients FE120C is well tolerated and is highly effective as up-front chemotherapy in relatively young patients with high-risk breast cancer, with a 90% (CI 74-98%) clinical objective response rate.

Locally advanced noninflammatory breast cancer

Treatment of locally advanced noninflammatory breast cancer has changed markedly over the past 50 years. Haagensen's description of the clinical signs that define inoperable and operable tumors was the first realization that radical surgery alone could not cure the majority of women with locally advanced disease. Studies of the use of local therapy alone (surgery or radiation therapy) confirmed that most patients developed both distant metastatic disease and a high rate of local-regional failure. Combination surgery and radiation therapy regimens improved local control but did not influence long-term survival. The advent of successful multimodal regimens incorporating systemic treatment (chemotherapy or chemohormonal therapy) as well as local therapy (surgery and radiation) has significantly improved disease-free and overall survival as well as local-regional control. The benefits of neoadjuvant and adjuvant chemotherapy regimens have been debated. Neoadjuvant therapy allows clinical and pathologic assessment of tumor response to the chemotherapy regimen. In addition, local-regional control seems to be improved, and reductions in the size of the primary tumor allow breast-preserving procedures, even in patients initially not believed to be candidates for resection. Longer follow-up of these conservatively treated patients will be needed, however, to determine whether local-regional control is preserved.

Intermediate doses of cyclophosphamide alone or following adriamycin in advanced breast cancer. A pilot study

Cyclophosphamide (CTX) is an active drug in breast cancer and presents a well-established dose-response relationship. To explore further this relationship, the present pilot study investigated the therapeutic efficacy of cyclophosphamide at intermediate dose in two groups of untreated patients with advanced breast cancer. Nine women received the drug alone at 3-4 g/m2 i.v. every 2 weeks for a total of three doses. The same dose schedule was also given to 11 women following the administration of four cycles of Adriamycin, at 75 mg/m2 i.v. every 3 weeks. We documented one partial remission in untreated women and four partial responses in Adriamycin-treated patients. The major toxicity was represented by leukopenia and neutropenia. Myelosuppression was relevant but of short duration, and the use of G-CSF appeared useful in controlling this side effect. In spite of the high dose intensity of the present cyclophosphamide dose schedule (9 g/m2 in 4 weeks), i.e., almost three times superior to that conventionally employed, present results do not suggest its superiority over the current chemotherapeutic regimens utilized in advanced disease.

Future prospects of neoadjuvant chemotherapy in treatment of primary breast cancer

Neoadjuvant chemotherapy in breast cancer was developed in the 1970s and is now used in patients with locally advanced or early resectable breast cancer. Early administration of systemic chemotherapy before local treatment in locally advanced breast cancer and early resectable breast cancer is intended to downstage the primary tumor to make subsequent local treatment (surgery/or radiotherapy) easier and, it is hoped, to eliminate occult distant micrometastases to prolong survival. Despite the theoretical and experimental data indicating the survival superiority of neoadjuvant chemotherapy over postoperative adjuvant chemotherapy, the role of neoadjuvant chemotherapy in treatment of breast cancer remains unclear. But for the effect of down-staging the primary tumor is confirmed, 60-80% of patients with resectable breast cancer can be treated by a breast conservation procedure after neoadjuvant chemotherapy. Large randomized clinical trials are needed to evaluate the survival benefit for neoadjuvant chemotherapy. The detection of clinical and new biological markers will be studied to select the nonresponders of neoadjuvant chemotherapy for alternative treatment approaches.

Multidisciplinary management of advanced primary and metastatic breast cancer

Combined modality therapy has become the treatment of choice for patients with primary breast cancer, including those with locally advanced breast cancer. Primary or induction chemotherapy, followed by surgery or radiation therapy or both, and adjuvant systemic therapy is a generally accepted strategy. Most tumors respond with a more than 50% decrease in tumor size, and approximately 70% of patients experience down-staging through primary chemotherapy. Breast conservation is possible for many patients with locally advanced breast cancer, and almost all patients initially are rendered disease free. Primary chemotherapy should be the initial choice of treatment for patients with locally advanced tumors, but it is unclear what the optimal sequence of subsequent therapies should be, or whether one or two local treatment modalities are necessary. The most dramatic example of the efficacy of these regimens was demonstrated in patients with inflammatory breast cancer. Previously a universally fatal condition, the natural history of this disease has been changed dramatically by the introduction of these combined modality therapies. Five-year survival rates of 35-60% commonly are reported, and it is likely that about one third of patients with this highly aggressive form of disease will survive beyond 10 years without recurrence. Combined modality therapy that includes primary chemotherapy provides appropriate local control, the possibility of breast conservation therapy, and, probably, an increased survival rate, at least for some subsets of patients with locally advanced breast cancer. The use of similar treatment strategies for early breast cancer is currently under evaluation. Hormone therapy and combination chemotherapy represent the main treatment approaches to metastatic breast cancer. Radiotherapy is also a useful palliative tool, especially for control of painful bone metastases and central nervous system involvement. Patient and tumor characteristics help in the optimal selection of systemic therapy. Palliative therapy for symptomatic control and prolongation of life also preserves a good quality of life. Dose-intensive chemotherapy is being evaluated as a treatment to increase complete response rates and cause remission consolidation. Clinical trials on several new and effective cytotoxic agents, as well as new hormonal compounds, are being completed and are showing encouraging preliminary results.(ABSTRACT TRUNCATED AT 400 WORDS)

Locally advanced breast cancer: defining an optimum treatment regimen

PURPOSE

This retrospective review examines response, local control and freedom from distant failure for patients with locally advanced breast cancer treated by chemotherapy and radiotherapy without routine surgery.

METHODS AND MATERIALS

67 patients were treated between January 1980 and December 1988 at Westmead Hospital, NSW, Australia. Median follow-up for surviving patients was 56 months. Four successive protocols evolved, each with three phases induction chemotherapy (adriamycin or novantrone, cyclophosphamide) (three cycles), radiotherapy then chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil) of progressively shorter duration. Radiotherapy and chemotherapy were concurrent in the fourth regimen.

RESULTS

Clinical complete response (disappearance of all known disease) after chemotherapy, radiotherapy and additional chemotherapy was 18%, 55% and 79% respectively. Seven additional patients subsequently underwent mastectomy (N = 2), local excision (N = 1) or a radiation boost (N = 4) for a total complete response rate of 90%. Twenty one patients (31%) failed to achieve a complete response (N = 7) or recurred locally (N = 14). The crude 2-year rate of local recurrence was 50% for tumors > 10 cm (N = 10) and 14% for smaller tumors (n = 57) and was not influenced by protocol. Two-year actuarial freedom from distant failure was 67% at 2 years.

CONCLUSION

Local control can be achieved for patients with locally advanced breast cancer with a primary tumor < 10 cm using chemotherapy and radiotherapy without routine mastectomy.

External and interstitial radiation therapy of locally advanced carcinoma of the breast

The present report concerns 164 cases of locally advanced breast cancer (stage III), treated between December 1977 and January 1987. The local therapy consisted exclusively of radiation therapy including external beam irradiation (60Co) up to 45-50 Gy supplemented with a boost, delivered either by interstitial 192Ir (30-40 Gy) or by external irradiation from limited fields (15-22 Gy). Eighty-one patients also received adjuvant systemic chemotherapy. A total of 51 local failures (31%) occurred. The actuarial rate of survival with local tumor control was 53% at 5 years and 49% at 6.5 years. A total of 69 patients developed distant metastases (42%). The actuarial survival without distant failure was 43% at 5 years and 37% at 6 years. The actuarial survival rate at 5 years was 53% and 38% at 7 years. The cosmetic results were excellent in 58 patients and poor in 13 patients (9.7%). The result suggests that stage III breast cancer can be satisfactorily treated with radiation therapy alone as local treatment.

Exclusive radical radiation therapy in breast carcinoma

We present the results of 186 breast cancer patients treated initially for locoregional disease by radiotherapy alone, combining cobalt therapy with external electron beam or interstitial iridium implants. According to the TNM classification, the patients were distributed as follows: 3 T1N0, 2 T1N1, 33 T2N0, 36 T2N1, 16 T3N0, 26 T3N1, 6 T3N2, 14 T4N0, 29 T4N1, 9 T4N2 and 12 T4N3. The 5- and 10-year survival rates (52.7% and 36.5%, respectively, for all patients) were directly correlated with the size and location of the breast tumor, and the extent of lymph node involvement. Locoregional recurrence was observed in 39.8% of the cases, metastasis alone in 26.8% of the cases, and a combination of local recurrence and distant metastasis in 14.5% of the cases. The local recurrences and metastases were directly correlated with the extent of locoregional involvement. Late complications and sequelae were mostly minor and occurred in less than 25% of the cases; severe sequelae occurred in no more than 2% of the cases. They depended on the initial tumor volume and the tumor dose. Our results, along with those in the literature, indicate that radiotherapy administered alone is a valid therapeutic option in breast cancer.

Comprehensive management of locally advanced breast cancer

The definition of locally advanced breast cancer includes patients with large tumors, extensive regional lymph node involvement, or direct involvement of the skin or underlying chest wall. Most of these patients have very poor survival with standard treatment modalities, and over the past 20 years combined modality therapy has been used to improve local and systemic control. There is limited information suggesting that patients with operable locally advanced breast cancer have an improved survival if treated with surgery (or radiation therapy) followed by systemic chemotherapy, as compared with patients treated with local modalities alone. Uncontrolled trials strongly suggest that patients with any stage of locally advanced breast cancer achieve high response rates after induction chemotherapy. Most of these patients can be rendered disease free after combined modality therapy, and their disease-free and overall survival rates appear to be improved when compared with historical controls. These results are most impressive for patients with inflammatory breast cancer, a disease previously found to be uniformly lethal when treated with local modalities of therapy alone. More recently, 30% to 50% of these patients were alive and disease free 5 years after diagnosis, and a substantial percentage were in the same condition 10 years later. Combined modality therapies are the most appropriate approach to patients with locally advanced breast cancer. Much additional research must be done to improve the results of these therapies and maximize the survival of patients with locally advanced breast cancer.

Prognostic factors in locally advanced noninflammatory breast cancer. Long-term results following primary chemotherapy

Since 1973 we have treated T3b-T4 (stage III) breast cancer with various forms of multidisciplinary approaches through prospective trials. The present report analyses the 10-year results of 277 patients. Primary chemotherapy consisted of adriamycin plus vincristine given for three or four cycles prior to high-energy irradiation or surgery. In 205 of 277 (74%) additional chemotherapy was planned following the local-regional modality. Primary chemotherapy yielded complete plus partial remission in 62% (CR 7%). Long-term freedom from progression and overall survival were significantly improved by the addition of chemotherapy following local-regional treatment (radiotherapy or surgery). Further chemotherapy was able to significantly affect treatment outcome when it was analyzed both singly and in the presence of other prognostic variables. Thus, in our experience, the variables significantly affecting the 10-year results were represented by duration of treatment and tumor cell burden expressed by size of primary malignancy and clinical nodal status. Locally advanced breast cancer appears a pleomorphic disease difficult to control over a long period of time because of its frequent presentation with bulky tumor and the very high risk of disseminated micrometastases. Thus, the management of this stage of disease almost invariably requires a multidisciplinary approach.

Locally advanced breast cancer current status and future directions

Patients described as having locally advanced breast cancer comprise a heterogeneous group of patients with variable clinical presentations. Systematic evaluation of patients with these presentations has been limited, with much of our current understanding based on retrospective reviews. Prospective pilot studies have demonstrated the feasibility of multimodality therapy. However, there have been few well-conducted randomized trials in this setting. Comparison of results among studies is made difficult by the varying eligibility criteria and the way in which the data are reported. The use of common and consistent definitions of operable and inoperable disease is necessary for a more uniform understanding of the therapeutic interventions necessary for a given patient within this broad category of Stage III or locally advanced breast cancer. There are a variety of opportunities for clinical research activities in this group of patients including tests of hormonal recruitment or synchronization, high dose chemotherapy requiring autologous bone marrow transplantation, perioperative or preoperative chemotherapy, and alternating chemotherapy with short course radiotherapy. The integration of clinical information with biological characteristics of the tumor such as cytokinetics, oncogene amplification, and hormone receptors will be an important and necessary focus of future investigation in this disease.

The efficacy of combined chemotherapy and radiotherapy in advanced non-metastatic breast cancer

Thirty-five patients with locally advanced (inoperable) breast cancer have been treated based on a regimen of chemotherapy-radiotherapy-chemotherapy. At the completion of all treatment a complete remission rate of 86% was achieved with acceptable toxicity. At a median follow-up of 24 months (range 4-60), relapse at the site of bulk disease occurred in 17% (10% isolated loco-regional relapse) and relapse at distant sites in 34%. The median relapse-free survival was 36 months and the median survival has not yet been reached. Following initial promising results in terms of loco-regional disease control in this group of high-risk patients, the protocol was extended to include 34 patients defined as having locally extensive disease. All patients in this subgroup had undergone a modified radical mastectomy and were categorized as (a) patients in whom the pre-operative clinical findings merited (in our opinion) inclusion in the category of locally advanced (inoperable) disease, (b) patients in whom the primary was operable but in whom extensive involvement of axillary nodes was found (greater than 10 nodes positive or greater than or equal to 70% nodes positive if less than 10 nodes found) and (c) patients without the above characteristics with a primary tumor greater than 8 cm. At a median follow-up of 23 months (range 4-48), loco-regional recurrence occurred in one patient (3%) but distant relapse occurred in 21%. Relapse-free and overall survival was not significantly different to that found in patients with locally advanced disease who did not undergo mastectomy.

Chemotherapy with estrogenic recruitment and surgery in locally advanced breast cancer: clinical and cytokinetic results

Thirty-nine patients with locally advanced breast cancer (T3b-4, N1-3 or inflammatory carcinoma) received 3 cycles of induction chemotherapy with estrogenic recruitment before surgery. The therapeutic regimen consisted of diethylstilbestrol (DES) orally on days 1-3, 5-Fluorouracil + Doxorubicin + Cyclophosphamide on day 4 q 21 days (DES-FAC). After surgery 6 additional cycles of chemotherapy (3 DES-FAC alternating with 3 DES-CMF with Methotrexate + F and C as in FAC) were administered. The objective response rate was 71.8% with 15.4% CR, and 56.4% PR; after surgery 36/39 (92.3%) patients were rendered disease-free. So far, 13 of 26 patients in stage IIIb have relapsed (9 of 13 with inflammatory carcinomas). Three-year survival and progression-free survival are 60% and 53.5%, respectively. Twenty-three of the 39 patients were subjected to serial tumor biopsies during the first DES-FAC regimen to allow for tumor-cell kinetic studies during DES and chemotherapy. A significant estrogenic recruitment occurred in 16 patients (69.6%), irrespective of estrogen-receptor status. At surgery, 3-4 weeks after induction chemotherapy, tumor proliferative activity was significantly depressed in comparison to basal values. These results indicate that breast cancer cells can be recruited in vivo with DES and that chemotherapy following estrogenic stimulation is effective and feasible with acceptable toxicity.

Primary radiation therapy for locally advanced breast cancer

The optimal local-regional treatment for patients with Stage III breast cancer has not been determined. To evaluate the effectiveness of radiation therapy as local treatment for such patients, the results of 192 patients (five with bilateral disease) treated with radiation therapy without mastectomy between July 1, 1968 and December 31, 1981 were reviewed. Excisional biopsy (gross tumor removal) was performed in only 54 of the 197 breasts. Patients typically received 4500 to 5000 cGy in 5 weeks to the breast and draining lymph nodes; a local boost to areas of gross disease was delivered to 157 patients. Multi-agent chemotherapy was given to 53 patients. The median follow-up was 65 months. The actuarial probability of survival for the entire group was 41% at 5 years and 23% at 10 years. The probability of relapse-free survival (RFS) was 30% at 5 years and 19% at 10 years. The addition of multi-agent chemotherapy was associated with a significantly improved 5-year RFS (40% versus 26%, P = 0.02). The 5-year survival rate was 51% for patients who received adjuvant multi-agent chemotherapy and 38% for patients who did not (P = 0.16). The actuarial rate of local-regional tumor control (not censored for distant failure) for all patients was 73% at 5 years and 68% at ten years, and the crude incidence of local-regional control was 78%. Local-regional tumor control was principally influenced by radiation dose. Patients who received 6000 cGy or greater to the primary site had a better 5-year rate of control in the breast than did patients who received less than 6000 cGy (83% versus 70%, P = 0.06). Significant complications were seen in 15 patients (8%); these included moderate or severe arm edema in six patients and brachial plexopathy in four patients. Cosmetic results at last evaluation were excellent or good in 56% of evaluable patients, fair in 25%, and poor in 19%. It is concluded that high-dose radiation therapy without mastectomy is an effective means of controlling local-regional tumor in patients with locally advanced breast cancer.

Adjuvant chemo- and hormonal therapy in locally advanced breast cancer: a randomized clinical study

Between 1977 and 1980, 118 breast cancer patients with locally advanced disease, T3B-4, any N, M0 or T1-3, tumor positive axillary apex biopsy, were randomized to one of three arms: I: radiotherapy (RT) to the breast and adjacent lymph node areas; II: RT followed by 12 cycles of cyclophosphamide, methotrexate, 5 fluorouracil (CMF) and tamoxifen during the chemotherapy period; III: 2 cycles of adriamycin and vincristine (AV), alternated with 2 cycles of CMF, then RT, followed by another 4 cycles of AV, alternated with 4 CMF; tamoxifen during the entire treatment period. The median follow-up period was 5 1/2 years. The adjuvant chemo- and hormonal therapy did not improve the overall survival; the 5-year survival was 37% for all three treatment arms. There was no statistically significant difference in RFS between the three modalities, nor when arm I was compared to arm II and III together, p = 0.11. Local recurrence (LR) was observed in 24 of the 86 patients (28%) who had reached complete remission (CR). LR was not statistically different over the three treatment arms. In 18 of the 24 patients with LR, distant metastases appeared within a few months from the local recurrence. In arm III, the CR rate after 4 cycles AV plus CMF and RT hardly changed after another 8 cycles of chemotherapy. The menopausal status did not influence the treatment results. Dose reduction in more than 4 cycles of chemotherapy was accompanied by better results, p = 0.04.

IN CONCLUSION

adjuvant chemo- and hormonal therapy did not improve RFS and overall survival. These findings do not support the routine use of adjuvant chemo- and endocrine therapy for inoperable breast cancer.

The role of radiation therapy in the management of locally advanced carcinoma of the breast

Current management of patients with locally advanced breast cancer is not satisfactory. Establishing local tumor control is a problem with either surgery or radiation therapy alone. There is some suggestion that the two modalities should be combined when possible. Regardless of local control, distant metastasis is quite common. An example of the results of primary radiation therapy for locally advanced breast cancer is described in the study from the Joint Center for Radiation Therapy where the actuarial rate of local control was 54% and the 5-year survival was 30%. Recently, adjuvant chemotherapy has been introduced in the management of these patients. The authors' studies indicate that adjuvant chemotherapy not only increases the 5-year survival, but also improves local tumor control. At this time it is unclear whether adjuvant chemotherapy has improved the cure rate or simply increased the time to treatment failure. Current studies are directed toward the optimum interfacing of local treatment and adjuvant chemotherapy. It is only through an aggressive approach to both the local disease as well as the subclinical distant metastases that an increased cure for patients with locally advanced breast cancer will be achieved.

Chemotherapy of breast cancer: current views and results

The paper critically reviews major accomplishments achieved with the use of chemotherapy in the treatment of various stages of breast cancer. In spite of innumerable clinical trials, there is no evidence that in advanced breast cancer the addition of more drugs, either in concomitant, sequential or alternating fashion, to known effective combinations, was able to significantly improve the incidence and the magnitude of objective response or its median duration or survival. The addition of endocrine therapy to chemotherapy has failed so far to improve the most important end-point, i.e. total survival. Second-line chemotherapy is only moderately effective for a fairly short period of time. Thus, in women with advanced breast cancer excessive tumor cell burden and permanent drug resistance remain the major obstacles to obtaining complete remission and long-term disease free survival. In the adjuvant setting, the initial trials with combination chemotherapy have achieved consistent results, particularly in women with minimal axillary node involvement. Unless a woman has undergone a surgical breast-saving procedure, postoperative radiotherapy does not appear to play an important therapeutic role, either with or without concomitant or sequential chemotherapy. Present results would suggest that in advanced breast cancer little progress can be expected in the near future. Therefore, medical oncologists should focus on the correct application of established drug regimens, using a sequential flow of hormonal manipulations and cytotoxic chemotherapy. In high-risk groups, full dose adjuvant polydrug therapy given for a relatively short period of time appears to be at present the only means able to significantly decrease the failure rate following local regional treatment. Present consistent achievements, which appear devoid of important delay morbidity (e.g. cancerogenesis, chronic organ damage) will require further clinical research to identify more effective and less toxic treatments.