Racial differences in the use of contralateral prophylactic mastectomy among women undergoing BRCA1/BRCA2 genetic testing

6542

Background: Patients often use both positive and negative BRCA1/BRCA2 genetic test results to aid in surgical management decisions, but little is known about the existence of racial/ethnic differences in the use of genetic test results. The objective of this study was to evaluate differences in rates of contralateral prophylactic mastectomy (CPM) by race. Methods: A retrospective chart review was performed. Women with a personal history of breast cancer who underwent genetic testing for the BRCA1 and BRCA2 genes at our institution between 1996 and 2008 and were eligible for CPM were included in the study. Genetic test result, race/ethnicity as reported by the patient, years of follow-up since receipt of test result, and decision regarding CPM were recorded. Pearson chi square analyses and Fisher's exact tests were performed to test for significance. Results: 881 women were included in the study. Twenty percent (n = 180) were found to have a BRCA1 or BRCA2 mutation, while 80% (n = 701) were found to have an uninformative negative result. The study population was 87% (n = 771) Caucasian; 7% (n = 58) African American; and 6% (n = 52) Hispanic. Median follow up time was 3 years. There were no significant differences in either follow up time or percentages of BRCA positivity, based on race/ethnicity. Among those with a positive result, 45% (67/149) of Caucasians, 33% (5/15) of African Americans, and 50% (8/16) of Hispanics underwent CPM, but this was not statistically significant. Caucasians and Hispanics with positive results were significantly more likely than their counterparts with negative results to undergo CPM (Caucasians, 45%; 67/149 vs. 16%; 101/622; p<.001; Hispanics, 50%; 8/16 vs. 11%; 4/36; p = 0.004), but this same trend was not observed among African Americans (positive results, 33%; 5/15 vs. negative results, 14%; 6/43; p = 0.10). Conclusions: Among those with a BRCA1/BRCA2 mutation, there does not appear to be any significant difference in the use of CPM based on race/ethnicity. However, Caucasians and Hispanics appear to be more likely than African Americans to use the results of genetic testing to make surgical management decisions.

No significant financial relationships to disclose.

Correlations of estrogen receptor (ER) related genomic transcription and ER gene expression with increasing AJCC stage of ER-positive breast cancer

1044

Background: Advanced stages of ER-positive breast cancer may have decreased tumor dependence on estrogen, possibly due to biological selection and/or progression. The sensitivity to endocrine therapy (SET) index measures transcriptional activity of the ER genomic pathway (165 ER-related genes). We investigated whether expression of genes for receptors ER (ESR1), progesterone receptor (PGR), or HER-2 (ERBB2), the SET index, or a housekeeper gene (GAPDH) vary by stage of ER-positive breast cancer. Methods: We evaluated gene expression profiles (Affymetrix U133 microarrays, Affymetrix, Santa Clara, CA) from 956 patients’ clinical samples of ER-positive breast cancer, including 290 new samples profiled at MDACC and 666 samples from published datasets. Microarray data were uniformly normalized, log-transformed, and expression levels for single genes and the SET index were compared to pathologic AJCC stage (315 patients were stage I, 362 stage IIA, 151 stage IIB, 29 stage III, 27 stage IV at initial presentation, and 72 stage IV previously treated and/or at relapse) using a median ordered regression analysis (p < 0.05 was significant). Results: SET index significantly decreased with advancing pathologic stage (p < 0.001), and PGR expression levels showed a similar, but lesser, effect (p = 0.014). However, expression levels of ESR1 and ERBB2 did not vary by stage. Overall, GAPDH gene expression increased with stage (p < 0.001), but that effect was only observed in stages III and IV. Expression of these genes was not significantly different between stage IV disease at initial presentation or at relapse. Conclusions: Expression levels of ESR1 and ERBB2 receptor genes did not vary, but ER-related genomic transcription (SET index and, to a lesser extent, PGR) declined significantly with increasing pathologic stage. This suggests that ER-positive breast cancer tends to have less transcriptional dependence on estrogen with increasing pathologic stage. The observed increase in expression of GAPDH in stages III and IV might reflect higher metabolic activity in advanced ER-positive breast cancer and deserves further study.

[Table: see text]

Value of adjuvant radiation therapy in breast cancer patients with one to three positive lymph nodes undergoing a modified radical mastectomy and systemic therapy

507

Background: Whether adjuvant radiation therapy should be utilized for patients (pts) with early stage breast cancer with up to 3 positive axillary lymph nodes treated with mastectomy and systemic therapy is controversial. This retrospective study was performed to determine if adjuvant radiation therapy had an impact on survival for this cohort of pts. Methods: 4240 pts with T1–2N0–1 breast cancers, diagnosed between 1980–2007, who underwent either mastectomy without adjuvant radiation therapy or segmental mastectomy with adjuvant radiation therapy were identified. All pts received systemic treatment. Women with >3 positive axillary lymph nodes were excluded. Overall (OS) and distant disease free survival (DDFS) were estimated using the Kaplan-Meir product method. Cox proportional hazards were used to determine associations between OS/DDFS and type of surgery after controlling for pt and disease characteristics. Results: 1336 (18.8%) had T1N0 disease, 1114 (26.27%) had T2N0 disease, 989 (23.33%) had T1N1 disease and 801 (18.89%) had T2N1 disease. Median follow-up was 54 months.5- year DDFS among women who underwent mastectomy and segmental mastectomy was 81% (95% 78%-83%) and 86% (95% CI 84%-87%), respectively (p < 0.0001). In the Cox analysis, pts who had mastectomy without radiation had a significantly increased risk of distant recurrence (HR= 1.39, 95% CI 1.14–1.70, p= 0.0013) than pts treated with segmental mastectomy and radiation. When looking at subgroups, no significant difference in DDFS was observed between the two groups in pts with lymph node negative disease. However, for pts with 1–3 positive lymph nodes, pts treated with mastectomy without radiation had significantly increased risk of distant recurrence compared to pts treated with segmental mastectomy with radiation (HR=1.614, 95% CI 1.198–2.177, p= 0.002). This difference was most pronounce in the subset of patients with T2N1 disease (HR= 1.794, 95% CI 1.220–2.637, p=0.003). Similar trends were observed for OS. Conclusions: This study provides provocative evidence for benefit of radiation therapy among pts with 1–3 positive axillary lymph nodes who are treated with surgery and systemic therapy.

No significant financial relationships to disclose.

Phase I trial of escalating doses of weekly everolimus (RAD001) in combination with docetaxel for the treatment of metastatic breast cancer (MBC)

1066

Background: Inhibition of mTOR with everolimus (E) may improve efficacy in combination with docetaxel (D), but both drugs are metabolized by CYP3A4, thus a pharmacokinetic (PK) interaction may also exist. Methods: 15 patients (pts) with MBC were treated with docetaxel and everolimus using the continuous reassessment method (CRM) to determine maximum tolerated dose (MTD). Docetaxel doses were 40–75 mg/m2 IV on day 1 of a 21 day cycle. Everolimus doses were 20–50 mg PO on days 1 and 8 of a 21 day cycle (except cycle 2, where only day 8 was given to allow single agent PK analyses of both drugs). Response was measured every 2 cycles using RECIST. Results: Median age= 58 years and 77% of pts had >2 prior chemotherapies for MBC. Initially 2 of 2 pts treated (D= 75 mg/m2, E= 30 mg) developed DLT (neutropenic fever/infection), prompting a mandatory PK evaluation for all pts enrolled in subsequent cohorts. A second cohort of 3 patients (D=60 mg/m2, E=20mg) had no DLT, but no pts received day 8 of E due to grade 3–4 neutropenia. PK analyses demonstrated a 42% lowered (-42%) D clearance at the 60 mg/m2 in the presence of E (n=1). Subsequent cohorts were accrued at D=40 mg/m2 with escalating doses of E (Table). For the entire group, an 18% decrease (-18%) in D clearance was observed when D was administered concomitantly with E. High interpatient variability of D clearance was observed (range +16% to -135%). No pts had CR/PR, but 6 had SD>4 cycles and 2 had SD=8 cycles. Conclusions: Weekly everolimus appears to cause widely variable and unpredictable changes in docetaxel clearance making this combination unfeasible.

[Table: see text]

No significant financial relationships to disclose.

Development of new cancers in patients with DCIS: the M.D. Anderson experience

BACKGROUND

The purpose of this study was to describe clinical characteristics and outcome of mammographically and clinically detected new cancers in patients with previously diagnosed ductal carcinoma in situ (DCIS).

METHOD

Our database was searched to identify patients with a primary diagnosis of DCIS. Those with prior evidence of invasive carcinoma were excluded from the analysis. Cumulative incidence of new cancers was estimated according to the method of Gray. Survival times were estimated using the Kaplan Meier product limit method.

RESULTS

A total of 799 patients diagnosed and treated for DCIS were included in the analysis. Median age at diagnosis was 54 years (range 22-88 years) and median tumor size was 1.4 cm (range 0.2-15 cm). After a median follow-up of 2.9 years, 45 patients (5.6%) had a second event: 14 (31%) with in-situ and 31 (69%) with invasive disease. Median disease-free interval was 3.5 years (range 0.5-20.8 years). The majority of second events (63%) occurred in the opposite breast (P = 0.048) and the cumulative incidence at 5 years was 6.6%. Overall survival at 5 years was 97.4%; that for the second event was 76.1%. For mammography and self-palpation, respectively, the 5-year survival by method of detection of the second event was 63.2% and 100% (P = 0.08 with a 33% power to detect a difference).

CONCLUSION

Second events following DCIS occurs primarily in the opposite breast and have a negative impact on survival.

The impact of hormone receptor status on pathologic response of HER2-positive breast cancer treated with neoadjuvant chemotherapy with or without trastuzumab

533

Background: The aim of this study was to compare the extent of pathologic response in HER2-positive patients treated with standard neoadjuvant chemotherapy with or without trastuzumab according to hormone receptor (HR) status. Methods: The study included 199 patients with HER2-positive disease treated in clinical trials of neoadjuvant chemotherapy. Eighty-nine patients treated with 3- weekly paclitaxel and concurrent trastuzumab followed by 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) were compared with 110 patients treated with weekly or 3-weekly paclitaxel followed by FEC or FAC. Residual cancer burden (RCB), a measurement of residual disease (RD) from pathologic review of the primary tumor and lymph nodes, was classified as pathologic complete response (pCR), RCB-I (near-pCR, minimal RD), RCB-II (moderate RD), or RCB-III (extensive RD). RCB was compared between treatment groups according to HR status. Results: In HR-negative patients, similar pCR rates were achieved with weekly T/FAC as with 3-weekly T/FEC and trastuzumab (61% and 65%, respectively). However, in HR-positive patients, higher pCR rates were achieved with 3-weekly T/FEC and trastuzumab (47%) than with the weekly T/FAC (25%; p=0.04) or 3-weekly T/FAC (19%; p=0.01) ( Table 1 ). Near pCR (RCB-I) was slightly higher in HR-positive (26%) than in HR-negative patients treated with 3-weekly T/FEC and trastuzumab (11%; p=0.07). Conclusions: Patients with HR- negative/HER2-positive breast cancer had similar pathologic response rates from addition of trastuzumab to 3-weekly T/FEC or from weekly T/FAC chemotherapy. Patients with HR-positive/HER2-positive breast cancer obtained significant benefit from addition of trastuzumab to 3- weekly T/FEC, compared to 3-weekly T/FAC or weekly T/FAC. The combination of weekly T/FEC with trastuzumab as neoadjuvant chemotherapy should be evaluated.

[Table: see text]

[Table: see text]

Effect on patient outcome of residual DCIS in patients with complete eradication of invasive breast cancer after neoadjuvant chemotherapy

530

Background: To determine whether residual ductal carcinoma in situ (DCIS) after completion of preoperative chemotherapy affects the outcome of patients with hiostologically defined complete eradication of invasive cancer. Methods: Retrospective analysis of a database including 2,302 breast cancer patients treated prospectively with neoadjuvant chemotherapy at the UT MD Anderson Cancer Center between 1980 and 2004 was performed. The overall, disease-free and local recurrence-free survivals were compared for patients with no residual invasive or in situ cancer (pCR) and those with no residual invasive cancer but persistent in situ disease (pCR+DCIS). Results: The mean follow-up was 250 months. Of the 2,302 treated patients 78 (3.4%) had pCR, 199 (8.6%) had pCR+DCIS, and 2025 (88%) had residual invasive cancer. The 5-year (87.1% in both) and 10-year (81.3% vs 81.7%) disease-free survival rates were similar for cases with pCR and pCR+DCIS. The 5-year (91.9% vs. 92.5%) and 10-year (91.8% vs. 92.5%) overall survival rates were also similar and significantly better than the rate of patients with residual invasive cancer (74.4%, p<0.001). The 5-year local-regional recurrence-free survival rates were also not different for patients with pCR (92.8%, 95% CI: 86.1%-96.4%) and those with pCR+DCIS (90.9%, 95% CI: 77.3%- 96.5%), p=0.63. Conclusions: Residual DCIS in patients who experience complete eradication of the invasive cancer in the breast and lymph nodes does not adversely affect survival or local recurrence rate. Inclusion of cases with residual DCIS in the definition of pathologic complete response is justified when this outcome is used as early surrogate for long term-survival.

No significant financial relationships to disclose.

Trends in survival of stage IV breast cancer (BC) among Caucasian and African American (AA) BC patients (pts)

1000

Background: The aim of this review was to look at the trends in survival over time in patients(pts) with de novo stage IV BC and to identify factors that impact survival. Methods: We searched the SEER registry to identify pts with de novo stage IV breast cancer diagnosed between 1988 and 2003. Pts who were male, did not have microscopic confirmation of disease, had more than one primary, and who had a prior malignancy were excluded. Pts were divided into three groups based on their year of diagnosis separated into 5-year intervals: 1988 - 1993, 1994 - 1998, and 1999 -2003. Overall survival (OS) and BC specific survival (BCS) were calculated from the date of diagnosis to the date of death, last follow-up, or 12/31/03. Survival outcomes were estimated by the Kaplan-Meier method, and Cox models were fit to determine the characteristics that were independently associated with survival. Follow-up time was censored at 3 years for Cox analyses. Results: 15,438 pts were identified. 3796 pts were diagnosed from 1988–1993, 3954 from 1994–1998, and 7688 from 1999–2003. Median age was 62 years. Median follow-up was 16 months (mos) (range 0–191), 18 mos (range 0–199), and 11 mos (range 0–59) in periods 1988 - 1993, 1994 - 1998, and 1999 - 2003 respectively. Median OS was 18 mos overall and 16, 18, and 20 mos respectively for each time period. Median BCS was 23 mos overall and 20, 21, and 25 mos for each time period. In the multivariable model, more distant year of diagnosis, Grade 3 disease, higher number of positive LN, increasing age, being unmarried, ER- disease, PR- disease, and no surgery were all independently associated with worse BCS. The interaction term between ER and year of diagnosis was of borderline significance, indicating that over time, pts with ER+ disease had decreasing risk of death compared to patients with ER- disease (HR 0.98, 95% CI 0.96–1.00). An interaction term between race and year of diagnosis was significant, such that with each increasing year of diagnosis AA pts had increasing risk of death compared to whites (HR 1.04, 95% CI 1.01–1.07). Conclusions: The survival of de novo stage IV BC pts has modestly improved over time. Of concern, survival disparities between AA and white patients increased rather than diminished over time.

No significant financial relationships to disclose.

Mammography use in women age 80 and older with breast cancer

9039

Background: The guidelines for screening mammography use in patients age 80 years and older are not clear. The purpose of this study was to determine the effect of mammography use on stage and tumor size at breast cancer diagnosis. Methods: The study is a retrospective cohort using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. We evaluated 14,976 women aged 80 and older diagnosed with breast cancer between 1996–2002. Patients were divided into three cohorts based on screening mammography use in the 60 months prior to diagnosis: nonusers, non-regular users (1–2 mammograms), and regular users (3+). The effects of screening on tumor stage (0-I vs. II-IV) and size were determined by logistic regression and multivariate analysis of variance. Results: Regular mammography use for the age groups 80–84, 85–89, and >= 90 was 29%, 19%, and 9%, respectively. Among regular users of mammography, 26% presented with stage II or greater cancer while 64% of non-users presented with stage II or greater disease. On multivariate analysis, non-users were 4.7 (95% CI 4.26–5.14) times more likely to present with high-stage cancer. Non-users, non-regular users, and regular users had an adjusted mean tumor size of 5.08 (4.44–5.72), 3.26 (2.57–3.95), and 2.77 (2.02–3.51), respectively. Conclusions: Regular screening mammography among women aged 80 years and older is associated with earlier stage at presentation and smaller tumor size compared to mammography nonusers. Health care providers should consider discussing potential benefits of screening mammography with their older patients particularly for those without significant comorbidity.

No significant financial relationships to disclose.

Congestive heart failure (CHF) in older women treated with anthracycline (A) chemotherapy (C)

521

Background: There are little available data on the long-term cardiac safety of anthracycline chemotherapy in women over age 65, so we evaluated rates and predictors of CHF in this population of older women. Methods: We used data from the Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database and included women aged 66–90 years who were diagnosed with breast cancer from 1992–1999, had no other cancers, and no history of CHF. Multivariable Cox regression analysis was used to estimate the 5- and 10-year cumulative rates of CHF and to determine the factors independently associated with the development of CHF. Results: A total of 34,621 women were included in this observational study: 28,640 who received no C, 3253 who received non-A C, and 2728 who received A C. Women who received A tended to be younger, have lower comorbidity scores, and have more advanced disease than women treated with non-A chemo or women who did not receive chemotherapy (p<0.001 for each). By multivariable Cox regression analysis, the 5- and 10-year rates of CHF in women aged 66–70 years were 19% and 47% for the A C cohort, 14% and 33% for the non-A C cohort, and 12% and 28% for the no C cohort. The adjusted hazard ratio was 1.45 (95% CI 1.19–1.76) for A C versus other C and was 0.97 (95% CI 0.82–1.14) for no C versus other C. The rates of CHF were not statistically different among women in the older age cohorts, although selection biases were likely stronger. Other significant predictors of CHF included black race (HR 1.28, 1.17–1.40), increasing comorbidity, and preceding diagnosis of hypertension (HR 1.40, 1.34–1.47), diabetes (HR 1.23, 1.16–1.30), and peripheral vascular disease (HR 1.26, 1.19–1.34). Conclusions: Although women ages 66–70 treated with A tended to be healthier than women treated with other types of chemotherapy, the rates of CHF among women treated with A were significantly higher. The difference in rates of CHF continued to increase through 10 years of follow-up.

No significant financial relationships to disclose.

A new measurement of residual cancer burden to predict survival after neoadjuvant chemotherapy

536

Background: The strength of association between tumor response and survival is critical for neoadjuvant chemotherapy trials. Pathologic complete response (pCR) reliably predicts survival benefit, but residual disease contains a range of pathologic responses that likely contain different prognostic groups, including near complete response and resistance. Methods: Pathologic slides and reports were reviewed from 432 patients in two completed neoadjuvant trials: 1) fluorouracil, doxorubicin and cyclophosphamide (FAC) in 189 patients, and 2) paclitaxel followed by FAC (T/FAC) in 243 patients. Paclitaxel was administered as twelve weekly (n=126) or four 3-weekly cycles (n=117). Residual cancer burden (RCB) was calculated as an index that combines pathologic measurements of primary tumor (size and cellularity) and nodal metastases (number and size). We compared four RCB categories, from RCB-0 (pCR) to RCB-3 (chemoresistant), and post-treatment revised AJCC Stage (0-III) for prediction of distant relapse-free survival (DRFS) in multivariate Cox regression analyses (stratified by ER status). Results: The pCR rate was greater after T/FAC than FAC (24% vs. 16%, LR p<0.05), and after weekly (vs. 3-weekly) paclitaxel in T/FAC (30% vs. 16%, LR p<0.01). In patients with residual disease, RCB measurements were significantly lower after T/FAC than FAC (t-test, p<0.0001), but were not different between paclitaxel schedules in T/FAC. RCB was a continuous predictor of DRFS after T/FAC (HR=1.86, 95%CI 1.51–2.30) or FAC (HR=1.67, CI 1.38–2.01) with median follow-up 5 and 8 years, respectively. The resistant category RCB-3 predicted relapse more strongly than AJCC Stage III and identified a larger group of high-risk patients ( Table ). Conclusions: RCB is a new continuous measure of pathologic response that is defined from routine pathologic materials, represents the distribution of residual disease, is a significant predictor of DRFS, and defines chemotherapy resistance more effectively than revised AJCC Stage.

[Table: see text]

[Table: see text]

Acute myeloid leukemia (AML) in older women after adjuvant breast cancer therapy

560

Background: Adjuvant chemotherapy for breast cancer is associated with the development of secondary AML, but this risk in an older population has not been previously quantified. Methods: We queried data from the Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database for women who were diagnosed with nonmetastatic breast cancer from 1992–1999. We compared the risk of AML in patients with and without adjuvant chemotherapy (C), and by differing C regimens. The primary endpoint was a claim with an inpatient or outpatient diagnosis of AML (ICD-09 codes 205–208). Risk of AML was estimated using the method of Kaplan-Meier. Cox proportional hazards models were used to determine factors independently associated with AML. Results: 36,904 patients were included in this observational study, 4,572 who had received adjuvant C and 32,332 who had not. The median patient age was 75.3 (66.0–103.3). The median follow up was 63 months (13–132). Patients who received C were significantly younger, had more advanced stage disease, and had lower comorbidity scores (p<0.001). The unadjusted risk of developing AML at 10 years after any adjuvant C for breast cancer was 1.6% versus 1.1% for women who had not received C. The adjusted HR for AML with adjuvant C was 1.72 (1.16–2.54) compared to women who did not receive C. HR for radiation was 1.21 (0.86–1.70). HR was higher with increasing age but p>0.05. An analysis was performed among women who received C. When compared to other C regimens, anthracycline-based therapy (A) conveyed a significantly higher hazard for AML HR 2.17 (1.08–4.38), while patients who received A plus taxanes (T) did not have a significant increase in risk HR1.29 (0.44–3.82) nor did patients who received T with some other C HR 1.50 (0.34–6.67). Another significant independent predictor of AML included GCSF use HR 2.21 (1.14–4.25). In addition, increasing A dose was associated with higher risk of AML (p<0.05). Conclusions: There is a small but real increase in AML after adjuvant chemotherapy for breast cancer in older women. The risk appears to be highest from A-based regimens, most of which also contained cyclophosphamide, and may be dose-dependent. T do not appear to increase risk. The role of GCSF should be further explored.

No significant financial relationships to disclose.

Expression of PEA3 and lack of correlation between PEA3 and HER-2/neu expression in breast cancer

The ETS protein PEA3 functions as a transcription factor to regulate gene expression. Although members of the ETS family have been reported to be involved in tumor progression, ectopic expression of PEA3 has been shown to suppress tumor formation. Despite several studies demonstrated frequent expression of PEA3 and its high association with HER-2/neu and have suggested a potential role of PEA3 in breast cancer, contradictory result has shown that the PEA3 was associated with better survival rate in breast cancer. In the current study, we address this discrepancy by examining the expression of PEA3 and HER-2/neu on 289 archived breast cancer tumor tissues and their correlation with clinicopathologic factors and prognosis. The staining of PEA3 was further validated by in situ hybridization for PEA3 mRNA. We found PEA3 was positive in 22.2% (64/289) of all cases and only 25.6% (21/82) of HER-2/neu-overexpressing cases showed co-expression of PEA3. In contrast to HER-2/neu, PEA3 expression was not correlated with prognosis or major clinicopathologic factors, except for a negative correlation with lymphovascular permeation ( p=0.007). This study demonstrates that PEA3 expression is not correlated with HER-2/neu expression in breast cancer tumor tissues, nor is it associated with adverse clinicopathologic factors or prognosis.

Nuclear translocation of the pro-apoptotic Bcl-2 family member Bok induces apoptosis

The anti-apoptotic members of the Bcl-2 family, such as Bcl-2 and Bcl-XL, play a central role in preventing the induction of apoptosis via the intrinsic apoptotic pathway. It has been previously shown that induction of apoptosis by the pro-apoptotic Bcl-2 family member Bok is not antagonized by either Bcl-2 or Bcl-xL, suggesting that Bok might have a unique role in the apoptotic cascade. We showed here that human Bok is the only member of the Bcl-2 family to have a leucine-rich sequence indicative of a nuclear export signal within its BH3 domain. Western blot analysis of nuclear and cytoplasmic fractions identified Bok in both the nucleus and the cytoplasm of HEK 293T cells, HeLa cells, and breast cancer cells, and its nuclear concentration increased after treatment of those cells with leptomycin B, an inhibitor of the exportin Crm1. Immunocytochemistry of flag-tagged Bok confirmed its nuclear localization. Mutating the nuclear export signal of Bok by site-directed mutagenesis resulted in an increase in its nuclear localization and apoptotic activity. We also found that Crm1 interacted with wild-type Bok but not with the mutated form. These results suggest that nuclear export of Bok is a regulated process mediated by Crm1, and constitutes the first report of a link between the apoptotic activity and nuclear localization of a pro-apoptotic member of the Bcl-2 family.

Minimal clinical benefit of single agent Orathecin (Rubitecan) in heavily pretreated metastatic breast cancer

PURPOSE

The purpose of this phase II study was to evaluate the efficacy and tolerability of Orathecin, an oral camptothecin analog that has exhibited antitumor activity in breast cancer patients during preclinical studies.

METHODS

Sixteen patients with metastatic breast cancer previously treated with anthracycline and taxane were utilized in the study. Orathecin was administered orally at 1.5 mg/m2 /day for the first five consecutive days of the cycle followed by 2 days of rest on a 7-day schedule. The end points of the study were efficacy and toxicity.

RESULTS

The median age of the patients was 51 years (range, 35-73). Eight patients (50%) had multiple disease sites, and nine patients (56%) received more than three chemotherapy regimens. All patients were evaluated for toxicity, three patients were removed from the study for toxicity or disease progression prior to 8 weeks and were thus not evaluated for efficacy. The median follow-up was 110 days (range, 15-554). There were no responses to treatment. Five of the 13 evaluable patients (38%) had stable disease, eight (61%) had progressive disease. Most adverse events were mild to moderate in intensity. The median time to progression (TTP) for evaluable patients was 109 days (range, 56-374 days) (lower 95% C.I., 57 days). The median survival time was 272 days (lower 95% C.I., 209 days).

CONCLUSIONS

Orathecin at the dose and regimen used in this study resulted in no objective tumor responses for this heavily pretreated population. Accurate risk stratification strategies can improve patients' selection and contribute to determine the appropriate benefit of therapies in MBC.

Lower dose capecitabine has a more favorable therapeutic index in metastatic breast cancer: retrospective analysis of patients treated at M. D. Anderson Cancer Center and a review of capecitabine toxicity in the literature

BACKGROUND

Capecitabine is active against anthracycline- and taxane-pretreated metastatic breast cancer. Post-marketing use of capecitabine at the FDA-approved dose (2500 mg/m2/day) leads to unacceptable toxicity in many patients. Dose reductions anecdotally improve tolerability without compromising efficacy. This retrospective analysis was designed to verify these anecdotal reports.

PATIENTS AND METHODS

We retrospectively reviewed the records of 141 consecutive patients with metastatic breast cancer identified from pharmacy records as receiving capecitabine outside of a clinical trial between May 1998 and February 1999. Responses were defined as clinical improvement (ID), stabilization of disease (SD) for 6 weeks or longer, or progression (PD). Patients were grouped according to the starting dose level of capecitabine: A=2500+/-5% (dose range 2385-2560) mg/m2/day; B=2250+/-5% (range 2130-2350) mg/m2/day; C < or = 2000+5% (range 1000-2100) mg/m2/day. We also reviewed the safety profile of capecitabine at these doses and performed a safety review of capecitabine in phase II and III metastatic breast and colorectal cancer trials.

RESULTS

Clinical data were available for 113 patients (105 for response, 106 for toxicity). The median age was 52.5 years and the mean number of prior metastatic chemotherapy regimens was 2 (range 0-7). The mean capecitabine starting dose was 2220 mg/m2/day and the median number of cycles administered was 4 (range 1-19). The mean tolerated dose was 2040 mg/m2/day (range 960-2670). Grade 3/4 toxic effects at dose levels A, B and C, respectively, included palmar-plantar erythrodysesthesia (33%, 63%, 20%), diarrhea (13%, 12%, 3%), stomatitis (8%, 0%, 3%), and nausea/vomiting (4%, 6%, 5%). Forty per cent of all patients required capecitabine dose reductions; fewer patients treated with 2000 mg/m2/day required dose modification (28%). Five per cent of the patients required discontinuation of capecitabine owing to toxicity. Patients started at the lowest doses of capecitabine did not have poorer response rates or shorter time to progression.

CONCLUSIONS

This retrospective analysis supports a starting dose of 2000 mg/m2/day because of its superior therapeutic index; however, patients may still have toxic effects and individualization of dosing is necessary. A phase III, multicenter, randomized study to establish the safety and efficacy of different doses of capecitabine is urgently needed.

Docetaxel for treatment of solid tumours: a systematic review of clinical data

Docetaxel is a semisynthetic taxane, a class of anticancer agents that bind to beta tubulin, thereby stabilising microtubules and inducing cell-cycle arrest and apoptosis. Docetaxel was first approved for the treatment of anthracycline-refractory metastatic breast cancer in the mid-1990s. Since then, several randomised trials have reported improved time-to-progression, overall survival, or both in metastatic breast cancer treated with single-agent docetaxel or docetaxel-based combination regimens. Data from two adjuvant trials have shown a survival benefit with the addition of docetaxel to standard anthracycline-based regimens in patients with high-risk early breast cancer. In four randomised studies, docetaxel improved survival in locally advanced or metastatic non-small-cell lung cancer. Moreover, two trials have shown that docetaxel combined with estramustine or corticosteroids improves survival in metastatic androgen-independent prostate cancer. Here, we review major randomised phase III trials with docetaxel in the treatment of solid malignant disease.