Molecular and genetic markers in the local-regional management of breast cancer

Molecular Subtypes and Local-Regional Control of Breast Cancer

In the era of personalized medicine, there has been significant progress regarding the molecular analysis of breast cancer subtypes. Research efforts have focused on how classification of subtypes could provide information on prognosis and influence treatment planning. Although much is known about the impact of different molecular subtypes on disease-specific survival, more recent studies have investigated the role of the different molecular subtypes on local-regional recurrence. This is an area of active study, and in recent years there has been significant progress. This article describes outcomes among disease subtypes to aid in optimal surgical decision-making to improve local-regional control.

Selective Radiation Therapy for Ductal Carcinoma In Situ Following Breast-Conserving Surgery According to Age and Margin Width: Korean Radiation Oncology Group 11-04 and 16-02 Studies

Purpose

The optimal indications for omitting adjuvant radiation therapy (RT) after breast-conserving surgery are still controversial in ductal carcinoma in situ (DCIS) of the breast. The purpose of this study was to validate the role of postoperative RT in DCIS patients aged ≤50 years and with tumor margin widths of <1 cm, both of which have been proven to be high-risk features for recurrence in cohorts not receiving RT.

Methods

Using two multicenter retrospective studies on DCIS, a pooled analysis was performed among patients aged ≤50 years and with margin widths <1 cm. All patients underwent breast-conserving surgery. Two hundred thirty-two patients received postoperative RT, while 54 did not. The median follow-up period was 77 months (range, 2-190 months) and 70 months (range, 5-166 months) in the patients who received RT and those who did not, respectively.

Results

The patients who received RT had larger tumors (p<0.001), higher nuclear grade (p<0.001), closer margin width (p<0.001), and negative estrogen receptor expression (p=0.010) compared with those who did not receive RT. During the follow-up period, there were 17 ipsilateral breast tumor recurrences (IBTRs) as follows: invasive carcinoma in 10 patients and DCIS in seven. In the univariate analysis, the treatment with RT and human epidermal growth factor receptor 2 (HER2) status were significant risk factors for IBTR. The 7-year IBTR rates with and without postoperative RT were 3.6% and 13.1%, respectively (p=0.008). HER2-positive tumors had a higher IBTR rate than the HER2-negative tumors (7-year rate, 13.6% vs. 3.9%; p=0.003).

Conclusion

Postoperative RT following breast-conserving surgery significantly reduced the 7-year IBTR rate in the DCIS patients aged ≤50 years and with margin widths <1 cm. HER2 positivity was associated with increased IBTR in these patients.

How could breast cancer molecular features contribute to locoregional treatment decision making?

Systemic treatments are tailored to breast cancer (BC) heterogeneity, which is not yet taken into account for radiotherapy (RT) personalization. The primary objective of this review is to summarize existing data suggesting BC subtypes and genetic assays are prognostic and predictive biomarkers useful for RT decision-making and to provide implications for their incorporation into future translational and clinical research. The evidence suggesting that BC subtypes also exhibit distinct "locoregional recurrence (LRR)" patterns is retrospective but consistent and validated in over fifteen studies. The HER-2 positive and triple negative subtypes are the most susceptible to locoregional failure. The high risk of the HER-2 positive subtype can be reversed with trastuzumab administration. Very little is known on the subtypes' intrinsic radiosensitivity properties. Genetic assays have assessed retrospectively signatures' prognostic and predictive value in patients' cohorts (several coming from prospective studies) for LRR risk and radiotherapy (RT) benefit. Further confirmation is needed before their introduction into clinical routine. Evidence on the use of molecular biomarkers for adjuvant RT tailoring is emerging but needs validation and introduction into prospective studies. The plethora of modern RT options (partial breast irradiation, hypofractionation), as well as recent evidence pointing towards more extensive radiotherapy, demand introduction of biological features into clinical trials to improve therapeutic decisions. Open questions, such as tailoring of irradiation after neo-adjuvant chemotherapy in complete responders and the understanding of the interplay between local control, systemic recurrence and survival given modern systemic treatments, need to be addressed under the prism of biology within this heterogeneous disease. Intrinsic radiobiological properties within this heterogeneity need to be highlighted in order to further improve outcomes.

Technical innovation in adjuvant radiotherapy: Evolution and evaluation of new treatments for today and tomorrow

Recent innovations in breast cancer radiotherapy include intensity modulated radiotherapy, brachytherapy and intraoperative radiotherapy and current trials are seeking to evaluate their value in optimizing local control while maintaining cosmetic effects. Future clinical dividends in local control and survival may come from the identification of molecular signatures of breast cancer radiosensitivity, the development of predictive signatures and identification of immunohistochemical markers of risk of local recurrence. The importance of tumour heterogeneity is being increasingly recognized as an important factor in determining radiotherapy response and an improved understanding of the biology of the tumour microenvironment may identify targets that allow enhanced radiosensitisation or reversal of radioresistance when inhibited. This review describes recent developments in these areas.

Differences in Prognostic Factors and Failure Patterns Between Invasive Micropapillary Carcinoma and Carcinoma With Micropapillary Component Versus Invasive Ductal Carcinoma of the Breast: Retrospective Multicenter Case-Control Study (KROG 13-06)

PURPOSE

We designed the present study to investigate differences in prognostic factors and failure patterns between patients with invasive micropapillary carcinoma or carcinoma with micropapillary component (IMPC) and randomly matched patients with invasive ductal carcinoma (IDC) of the breast at multiple institutions of the Korean Radiation Oncology Group (KROG).

MATERIALS AND METHODS

This retrospective multicenter study was performed using subjects treated from January 1999 to November 2011. Female patients who had undergone curative resection for breast cancer without neoadjuvant chemotherapy were considered for this study. Exact matches were made for age (± 3 years), pathologic tumor and node stage, treatment method (surgery with or without radiotherapy), and period when surgery was performed (within 1 year) at the same institution.

RESULTS

A total of 534 patients were analyzed. The median follow-up period was 59 months in both groups. In the comparison of clinicopathologic characteristics, rates of lymphovascular invasion (LVI) and nuclear grade III were both significantly higher in IMPC than in IDC (P < .001, P = .01, respectively). During the follow-up period, recurrences developed in 40 patients with IMPC (15.0%) and 21 with IDC (7.9%). Locoregional recurrence (LRR) developed in 22 patients with IMPC (8.2%) and 10 with IDC (3.7%). The rate of distant metastasis did not differ between the 2 groups (P = .52). LRR-free survival (P = .03) and recurrence-free survival (P = .007) were significantly different between the 2 groups, but overall survival was not (P = .67).

CONCLUSION

IMPC is associated with a higher rate of LVI, high nuclear grade, and a propensity for LRR compared to IDC. Modification of the locoregional treatment modality might be needed in this pathologic subtype of breast cancer.

The 21-gene recurrence score complements IBTR! Estimates in early-stage, hormone receptor-positive, HER2-normal, lymph node-negative breast cancer

Clinicians have traditionally used clinicopathological (CP) factors to determine locoregional recurrence (LR) risk of breast cancer and have generated the IBTR! nomogram to predict the risk of ipsilateral breast tumor recurrence (IBTR). The 21-gene recurrence score (RS) assay was recently correlated with LR in retrospective studies. The objective of this study was to examine the relationship between the RS and IBTR!. CP characteristics of 308 consecutive patients who underwent RS testing at our institution were examined. IBTR! was used to estimate the risk of 10-year IBTR. Descriptive statistics were used to compare the RS with the estimated IBTR!. Given a low event rate in this cohort, actual IBTR rates were not reported. Most patients had stage I/II (98%) and grade I/II (77%) disease. Median age was 54 years (range, 30–78). Median IBTR! without radiation therapy was 10% (mean, 12% [range, 4-43%]). RS was low (<18), intermediate (18–30), and high (>30) in 52% (n = 160), 40% (n = 123), and 8% (n = 25) patients. Overall, IBTR! did not correlate with RS (P = .77). We saw no correlation between RS and IBTR! in patients with less than (P = .32) or greater than (P = .48) a 10% risk of IBTR. Interestingly, Ki-67 expression correlated with both IBTR! (P = .019) and the RS (P = .002). Further study is warranted to determine if the RS can provide complementary biological information to CP factors in estimating the risk of LR. Prospective studies evaluating this association may potentially allow for individualized treatment decisions.

Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) as a prognostic marker for local control in T1-2 N0 breast cancer treated with breast-conserving surgery and radiation therapy (BCS + RT)

Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) expression, involved in the regulation of translation, has been implicated to mediate resistance to chemotherapy and radiation in cancer cells in vitro. The purpose of this study was to evaluate the prognostic significance of IFIT1 protein expression in patients with breast cancer treated with Breast-Conserving Surgery and Radiation Therapy (BCS + RT). A tissue microarray was constructed with specimens from 282 women with node-negative, early-stage (I/II) breast cancer who were treated with BCS + RT. Immunohistochemistry was used to stain for the IFIT1 protein. Cytoplasmic IFIT1 protein expression levels were correlated with clinicopathologic factors, local relapse-free survival (LRFS), disease-free survival (DFS), and overall survival (OS). IFIT1 positivity was found in 123 (49%) of cases. The median follow-up time was 7.3 years. Eighty percent of the patients had T1 disease, 88% were human epidermal growth factor receptor 2 (HER2) negative, and 20% had triple-negative breast cancer (TNBC). IFIT1 positivity was associated with estrogen receptor negative status (p = 0.002), progesterone receptor negative status (p = 0.02), TNBC (p = 0.01), and HER2-positive status (p = 0.006). In univariate and multivariate analysis, IFIT1 positivity was associated with improved LRFS (p = 0.055 and p = 0.04, respectively). Using a log-rank test, IFIT1 positivity was found to be associated with improved LRFS (94% versus 85%, p = 0.046) but not DFS or OS at 10 years. On subset analysis of the TNBC patients, IFIT1 positivity was found to correlate with improved LRFS (100% versus 53%, p = 0.004) and DFS in (87% versus 49%, p = 0.048) at 10 years. Elevated IFIT1 protein expression is associated with improved LRFS. In addition, our data suggest that IFIT1 expression may help risk stratify patients with TNBC who may benefit from more aggressive therapy. As there is limited data on IFIT1 in breast cancer, additional work is needed to ascertain its significance.

Increasing national mastectomy rates for the treatment of early stage breast cancer

BACKGROUND

To study national trends in the mastectomy rate for treatment of early stage breast cancer.

METHODS

We analyzed data from the Surveillance, Epidemiology, and End Results database, including 256,081 women diagnosed with T1-2 N0-3 M0 breast cancer from 2000 to 2008. We evaluated therapeutic mastectomy rates by the year of diagnosis and performed a multivariable logistic regression analyses to determine predictors of mastectomy as the treatment choice.

RESULTS

The proportion of women treated with mastectomy decreased from 40.1 to 35.6 % between 2000 and 2005. Subsequently, the mastectomy rate increased to 38.4 % in 2008 (p < 0.0001). Simple logistic regression models demonstrated that mastectomy rates between 2005 and 2008 were moderated by age (p < 0.0001), marital status (p = 0.0230), and geographic location (p < 0.0001). Multivariate logistic regression analysis found that age, race, marital status, geographic location, involvement of multiple regions of the breast, lobular histology, increasing T stage, lymph node positivity, increasing grade, and negative hormone receptor status were independent predictors of mastectomy. Additionally, multivariate analysis confirmed that women diagnosed in 2008 were more likely to undergo mastectomy than women diagnosed in 2005 (odds ratio 1.17, 95 % confidence interval 1.13 to 1.21, p < 0.0001).

CONCLUSIONS

There is evidence of a reversal in the previously declining national mastectomy rates, with the mastectomy rate reaching a nadir in 2005 and subsequently rising. Further follow-up to confirm this trend and investigation to determine the underlying cause of this trend and its effect on outcomes may be warranted.

Patient selection for accelerated partial-breast irradiation (APBI) after breast-conserving surgery: recommendations of the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) breast cancer working group based on clinical evidence (2009)

PURPOSE

To give recommendations on patient selection criteria for the use of accelerated partial-breast irradiation (APBI) based on available clinical evidence complemented by expert opinion.

METHODS AND MATERIALS

Overall, 340 articles were identified by a systematic search of the PubMed database using the keywords "partial-breast irradiation" and "APBI". This search was complemented by searches of reference lists of articles and handsearching of relevant conference abstracts and book chapters. Of these, 3 randomized and 19 prospective non-randomized studies with a minimum median follow-up time of 4 years were identified. The authors reviewed the published clinical evidence on APBI, complemented by relevant clinical and pathological studies of standard breast-conserving therapy and, through a series of personal communications, formulated the recommendations presented in this article.

RESULTS

The GEC-ESTRO Breast Cancer Working Group recommends three categories guiding patient selection for APBI: (1) a low-risk group for whom APBI outside the context of a clinical trial is an acceptable treatment option; including patients ageing at least 50 years with unicentric, unifocal, pT1-2 (<or=30 mm) pN0, non-lobular invasive breast cancer without the presence of an extensive intraductal component (EIC) and lympho-vascular invasion (LVI) and with negative surgical margins of at least 2mm, (2) a high-risk group, for whom APBI is considered contraindicated; including patients ageing <or=40 years; having positive margins, and/or multicentric or large (>30 mm) tumours, and/or EIC positive or LVI positive tumours, and/or 4 or more positive lymph nodes or unknown axillary status (pNx), and (3) an intermediate-risk group, for whom APBI is considered acceptable only in the context of prospective clinical trials.

CONCLUSIONS

These recommendations will provide a clinical guidance regarding the use of APBI outside the context of a clinical trial before large-scale randomized clinical trial outcome data become available. Furthermore they should promote further clinical research focusing on controversial issues in the treatment of early-stage breast carcinoma.

Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b&c

PURPOSE

To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT).

PATIENTS AND METHODS

The present analysis included 1 000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b&c studies. Tissue microarray sections were stained with immunohistochemistry for p53 and BCL2. Median potential follow-up was 17 years. Clinical endpoints were locoregional recurrence (LRR), distant metastases (DM), overall mortality, and overall survival (OS). Statistical analyses included Kappa statistics, chi(2) or exact tests, Kaplan-Meier probability plots, Log-rank test, and Cox univariate and multivariate regression analyses.

RESULTS

p53 accumulation was not significantly associated with increased overall mortality, DM or LRR probability in univariate or multivariate Cox regression analyses. Kaplan-Meier probability plots showed reduced OS and improved DM and LRR probabilities after PMRT within subgroups of both p53 negative and p53 positive patients. Negative BCL2 expression was significantly associated with increased overall mortality, DM and LRR probability in multivariate Cox regression analyses. Kaplan-Meier probability plots showed a significantly improved overall survival after PMRT for the BCL2 positive subgroup, whereas practically no survival improvement was seen after PMRT for the BCL2 negative subgroup. In multivariate analysis of OS, however, no significant interaction was found between BCL2 and randomization status. Significant reductions in LRR probability after PMRT were recorded within both the BCL2 positive and BCL2 negative subgroups.

CONCLUSION

p53 was not associated with survival after radiotherapy in high-risk breast cancer, but BCL2 might be.

Current status of treatment for early-stage invasive breast cancer

Az emlőrák a nők leggyakoribb rákos megbetegedése. Évente több mint egymillió nő betegszik meg emlőrákban. Az emlőrákos morbiditás meredeken emelkedett a fejlett ipari országokban az utóbbi pár évtizedben, de a mortalitási ráta mostanában csökken. Az utóbbi a szervezett lakossági szűréseknek, a korszerű sebészi és sugárterápiás beavatkozásoknak és a hatékonyabb szisztémás kezeléseknek köszönhető. A fejlődés egyik legizgalmasabb területe az új terápiás szerek bevezetése a klinikai gyakorlatba. A célzott terápia (tirozinkinázok gátlása) rohamosan fejlődik. Korai (0./I./II. stádium) emlőrákban a daganatot műtéttel eltávolítják, és ezt követi az adjuváns kezelés. Az adjuváns kezelés célja a lokoregionális és távoli mikroszkopikus daganatdepozitok elpusztítása. A daganatos kiújulás kockázatának megbecsülésére prognosztikai faktorokat használunk. Az optimális individualizált kezelés meghatározását a prediktív faktorok segítik. A dolgozatban a korai emlőrák kezelésének jelenlegi helyzetét tárgyaljuk, beleértve az emlőmegtartó kezelést, a mastectomia utáni sugárkezelést, a hormon- és kemoterápiát, valamint a humán epidermális növekedési faktor receptor-2- (HER-2-) pozitív daganatok trastuzumabkezelését.

[Evidence-based radiotherapy in the treatment of early-stage invasive breast cancer: traditional clinical features and biomarkers]

Adjuvant radiotherapy after modified radical mastectomy and breast-conserving surgery for early-stage invasive breast cancer substantially reduces the risk of locoregional failure and is evidence-based. Using traditional clinical and pathological factors, patients can be classified into subgroups by the risk of locoregional recurrence. In the high-risk groups the absolute benefit of irradiation is larger. However, the patients are over-treated in every subgroup. Substantial proportion of the patients remains free of locoregional recurrence even in the absence of irradiation, and some patients develop locoregional recurrence despite postoperative irradiation. Molecular markers may provide sufficient information to allow accurate individual risk assessment to identify patients who might benefit from irradiation. Despite of hundreds of reports on tumor markers, results are controversial and the number of validated markers for clinical practice is small. Prognostic and predictive factors commonly used in radiotherapy practice are ER, PgR and HER-2. Adjuvant radiotherapy not only reduces locoregional recurrence rates but also improves cancer-specific survival in patients receiving systemic therapy. The highest mortality reduction is observed in mastectomy patients with good prognostic factors (<4 positive nodes, tumor size <2 cm, Grade 1 malignancy, ER- and PgR-positive, HER-2-negative). After mastectomy the chest wall, and after breast conserving surgery the ipsilateral breast are the sites at greatest risk of recurrence. The risk of axillary recurrence is low in patients undergoing axillary dissection. Axillary and supraclavicular recurrences generally forecast a grim prognosis, and they are indicators of distant dissemination. Improvement in survival resulting from the use of irradiation is more related to the prevention of local recurrences. Post-irradiation local recurrence increases the risk of mortality, but with good prognostic factors the 10-year survival is 80-90%. Patients with </=2 cm ipsilateral breast recurrence might receive a second conservative surgery. The radiation dose to the lung and heart can be significantly reduced by individualized CT-based treatment planning. The rate of Grade 3 atrophic dermatitis and fibrosis is 3-4%. The estimated incidence of ipsilateral breast angiosarcoma is less than 0.2%, but the mortality rate is high.

Immunohistochemical biomarkers in patients with early-onset breast carcinoma by tissue microarray

Young women with breast cancer have a poor prognosis, and the role of biologic markers in young women is not well defined. We investigated the association of estrogen receptor, progesterone receptor, Bcl-2, HER-2/neu, p53, and Ki-67 with clinicopathologic features and outcome in young women with breast cancer.

METHODS

A cohort of 103 patients with early-onset breast cancer treated with conservative surgery and radiotherapy were entered in this study. Age range was 25-45 years, and median follow-up was 8.7 years. Each of the paraffin-embedded specimens was immunologically stained for six biomarkers expression by a recently developed tissue microarray method.

RESULTS

The 10-year overall breast relapse-free and distant relapse-free survival rates were 82.7%, 84.6.4%, and 66.7%, respectively, with 14 local relapses and 26 distant metastases among the 103 patients evaluated. Positive expression of estrogen receptor, progesterone receptor, bcl-2, HER-2/neu, p53, and Ki-67 were 42.7%, 48.5%, 35.6%, 28.0%, 36.9%, and 39.7%, respectively. Tumor stage and nodal status were significantly associated with overall survival and distant metastasis-free rate in univariate and multivariate analysis. Progesterone receptor negativity and Ki-67 positivity were associated with distant metastasis. There was no statistically significant correlation between the six biomarkers and local relapse.

CONCLUSIONS

Progesterone receptor, Ki-67, tumor stage, and nodal status were prognostic factors for distant failure in early-stage breast cancer in young patients. Further studies are needed to find other biologic markers associated with local failure in this group of patients.

Racial differences in the incidence of BRCA1 and BRCA2 mutations in a cohort of early onset breast cancer patients: African American compared to white women

PURPOSE

To evaluate the frequency and distribution of BRCA1 and BRCA2 mutations in a cohort of young women with breast cancer and to compare the distribution of mutations as a function of race.

METHODS

After IRB approved informed consent, 170 white women and 30 African American women with known breast cancer diagnosed at a young age (45 years or less) underwent complete sequencing of the BRCA1 and BRCA2 genes. Each cohort represented approximately 40% of women of the same ethnic background aged 45 years or younger in a breast cancer database.

RESULTS

Of the 200 patients tested, 131 (65%) had wild type mutations, 34 (17%) had deleterious mutations, and 35 (18%) had variants of uncertain significance. There were no significant differences between the white and African American cohorts regarding the percentage of deleterious mutations (17% v 17%). However, most African American patients had mutations in BRCA2 (4/5, 80%), while most mutations in the white cohort were in BRCA1 (20/29, 69%). In addition, 46% of the African American women had variants of uncertain significance, compared to only 12% of the white cohort.

CONCLUSIONS

Young African American women with breast cancer have a similar frequency of deleterious mutations as white women, but have a significantly higher frequency of variants of uncertain significance. Review of these variants revealed that the majority were unlikely to be associated with disease risk or were likely to be polymorphisms. The implications for genetic testing and counselling in young women with breast cancer are discussed.

Bases génétiques de la radiosensibilité des cancers du sein

Local-regional radiation therapy is one of the major therapeutic means in the management of breast cancer. Three questions however arise from the important advances achieved in this domain in the past years. The first question concerns the possibilities to identify and overcome the radioresistance of a subset of tumours. The second question is how to recognize women likely to benefit from adjuvant radiation therapy, and therefore to diminish treatment indications in other groups. Finally, the third question is how to identify subjects at high risk for long term injury following breast irradiation, in order to adapt techniques and indications in such populations. The major advances of breast cancer molecular genetics in the past years should provide clinicians with tools to answer these important questions. In this paper, we review the molecular germline (BRCA1, BRCA2, ATM, ...) and somatic (p53, tyrosine kinase receptors, as well as actors of cell cycle, signal transduction, apoptosis, DNA repair ...) main bases of breast cancer radiosensitivity. Recent methods of exploration of the genetic background of both the host and the tumours (gene and protein expression profiles) are also reviewed as major tools of breast cancer management in the next few years.

Upregulation of bikunin in tumor-infiltrating macrophages as a factor of favorable prognosis in ovarian cancer

OBJECTIVE

This study was carried out to clarify the localization of bikunin, a Kunitz-type protease inhibitor, and relation between expression of individual bikunin protein and ovarian cancer progression.

METHODS

We performed a retrospective study on the immunohistochemical expression of bikunin, urokinase-type plasminogen activator (uPA) and macrophages (CD68) in surgical specimens derived from 89 ovarian cancer patients to investigate correlations between the expression of bikunin and the clinicopathologic features and the prognosis. Furthermore, bikunin and uPA levels were measured by immunoblot analysis.

RESULTS

Immunohistochemical staining revealed that the localization of bikunin was similar to that of CD68 for macrophages. We identified high expression of bikunin in 40 (45%) of 89 ovarian cancers. The results of Western blot analysis showed a significant correlation with immunohistochemical data. There was a significant inverse correlation between bikunin levels and uPA levels in ovarian cancer tissues. High bikunin expression was an independent predictor for disease-free survival (P = 0.040) and overall survival (P = 0.042). The 5-year survival rate of the 49 patients with low bikunin expression in ovarian cancers was 39%, whereas that of the other 40 patients with high bikunin expression was 63%. In addition, macrophage-derived bikunin protein was induced by exogenous IL-6.

CONCLUSION

Bikunin derived from tumor-infiltrating macrophages might be a prognostic indicator as an antiinvasive factor supplied from macrophages within and around the tumor possibly through down-regulation of tumor-associated uPA expression.

Molecular markers for prognosis after isolated postmastectomy chest wall recurrence

BACKGROUND

Local chest wall recurrence after mastectomy occurs in 10-20% of patients with operable breast carcinoma. The objective of the current study was to assess the prognostic value of molecular markers at the time of local recurrence and to compare these markers with clinical variables.

METHODS

Between 1975 and 1999, the authors treated 113 patients at their institution for postmastectomy chest wall recurrences with full-course external beam radiotherapy. Patients who presented primarily with lymph node recurrences or with simultaneous distant metastasis were excluded. Follow-up from the time of chest wall recurrence was 10.13 years. All clinical and pathologic data from the original diagnosis and from the time of chest wall recurrence were entered into a computerized database. Paraffin-embedded tumor specimens from the chest wall recurrences were available for 43 patients and were constructed into tissue microarrays for immunohistochemical staining of estrogen receptor, progesterone receptor (PR), p53, HER-2/neu, and cyclin D.

RESULTS

Overall survival after chest wall recurrence for the entire cohort was 46% at 5 years and 28% at 10 years. The distant metastasis-free survival rate was 49% at 5 years and 40% at 10 years. Local-regional control of disease was achieved in 79% of patients at 10 years. In multivariate analysis, significant factors for distant metastasis after local recurrence were time to recurrence (< 2 years from the original diagnosis to chest wall recurrence) and PR status (distant metastasis-free survival rate: 84% [PR-positive] vs. 38% [PR-negative]; P = 0.007). The only significant factor for local-regional disease progression was HER-2/neu status. Patients with positive HER-2/neu status had a local-regional progression-free rate of 59%, compared with 92% for patients with negative HER-2/neu status.

CONCLUSIONS

The prognosis for patients after local-regional recurrence of breast carcinoma is relatively poor. Longer time to local recurrence and positive PR status were associated with favorable distant metastasis-free rates and long-term survival. Positive HER-2/neu status was associated with poorer local-regional control of disease. Implications for systemic therapy and further studies are discussed.

Molecular markers in clinical radiation oncology

Radiation therapy plays a critical role in the management of a majority of patients diagnosed with cancer. Identification of factors that help predict which patients are at risk for relapse within the irradiated field remains an active area of investigation. Although conventional clinical and pathologic factors have been helpful in identifying risk and guiding clinical decision-making for both local and systemic management, there is clearly a need to identify additional prognostic markers, which can aid in refining our treatment strategies and improving outcomes. A substantial amount of research efforts have been devoted to identifying molecular markers for prognostic and therapeutic strategies. The recent emergence of a powerful armamentarium of molecular tools has resulted in rapid expansion of our fund of knowledge and understanding of the molecular biology underlying tumor behavior and response. While a majority of these efforts have been focused on risk factors for metastatic disease and survival, there is a rapidly growing body of literature focused on molecular factors associated with radiation resistance and locoregional failure. In this review, we summarize recent advances and the available literature evaluating molecular markers as they relate to radiation sensitivity of solid tumors. Literature regarding the potential application of expression of genes related to apoptosis, angiogenesis, cell cycle, DNA repair and growth factors will be reviewed. Some of the basic biology and laboratory evidence demonstrating how the marker relates to radiation response and available correlative clinical studies employing these markers as prognostic tools are presented. The majority of molecular markers that have potential clinical significance with respect to radiation sensitivity and local control will be highlighted.

Role of HER2 in wound-induced breast carcinoma proliferation

OBJECTIVE

Clinical and experimental data have suggested that surgical removal of primary tumours promotes the growth of metastatic lesions. We assessed the effect of surgery on proliferation of breast carcinomas, in particular those overexpressing HER2 oncoprotein.

METHODS

Proliferation of breast carcinoma cells was assessed by MIB-1 immunohistochemistry in sections of primary breast carcinomas and in residual tumour found in re-excision specimens, and in in-vitro cell lines by colorimetric assay. Epidermal growth factor (EGF)-like growth factors were measured by displacement of radiolabelled EGF from its receptor. Cellular damage was measured in terms of creatine phosphokinase level. Downmodulation of HER2 was investigated by cytoplasmic expression of anti-HER2 antibody and by inhibition with anti-HER2 antibody trastuzumab.

FINDINGS

Residual breast carcinomas that had been surgically removed within 48 days after first surgery showed a significant increase in proliferation if they were HER2-positive. Wound drainage fluid and postsurgical serum samples from patients stimulated in-vitro growth of HER2-overexpressing breast carcinoma cells. Removal of HER2 from the cell membrane led to a striking reduction of the induced proliferation. The amount of EGF-like growth factors in post-surgical serum samples, as well as the extent of drainage-fluid-induced proliferation, directly correlated with the amount of surgical damage assessed by creatine phosphokinase levels (r=0.77, p=0.002 and r=0.69, p=0.009, respectively). Treatment of HER2-positive tumour cells with trastuzumab before adding the growth stimulus abolished drainage-fluid-induced proliferation.

INTERPRETATION

HER2 overexpression by breast carcinoma cells has a role in postsurgery stimulation of growth of breast carcinoma cells.