Gene polymorphisms in cyclophosphamide metabolism pathway,treatment-related toxicity, and disease-free survival in SWOG 8897 clinical trial for breast cancer

PURPOSE

There are no established genetic markers for prediction of outcomes after cyclophosphamide (CP)-containing adjuvant therapy for breast cancer. In an ancillary study to a SWOG (Southwest Oncology Group) trial (S8897), we investigated functional polymorphisms in 4 genes in CP pharmacokinetic pathways in relation to hematologic toxicity and disease-free survival (DFS).

EXPERIMENTAL DESIGN

Germline DNA was available from 458 women who were at high risk of relapse and was randomized to CAF (CP, intravenous doxorubicin, and 5-fluorouracil) versus CMF (CP, intravenous methotrexate, and 5-fluorouracil) ± tamoxifen, and from 874 women who had a presumed favorable prognosis and did not receive adjuvant therapy. Odds ratios for grade 3 and 4 hematologic toxicity in the treated group and hazard ratios for DFS associated with selected functional polymorphisms in CYP2B6CYP3A4GSTA1 and GSTP1 were estimated by logistic regression and Cox proportional hazard regression.

RESULTS

Compared with women with AA genotypes, those with at least 1 GSTP1 variant G allele had reduced risk of grade 3 and 4 neutropenia [odds ratios (OR) = 0.63, 95% CI = 0.41-0.97] and leucopenia (OR = 0.59, 95% CI = 0.39-0.89). No other associations between single nucleotide polymorphisms and toxicity or survival were found in the treated or untreated group.

CONCLUSION

Known genetic variants in genes involved in CP pharmacokinetics may not have major effects on DFS in breast cancer patients. The lower risk of developing high-grade hematologic toxicity among women with variant GSTP1 alleles suggests that genetic markers in combination with clinical factors may be useful in defining a subgroup of women who are less susceptible to adverse hematologic toxicities with CP-containing therapies.

Randomized, controlled trial of cyclophosphamide, methotrexate, and fluorouracil versus cyclophosphamide, doxorubicin, and fluorouracil with and without tamoxifen for high-risk, node-negative breast cancer: treatment results of Intergroup Protocol INT-0102

PURPOSE

We evaluated the efficacy of cyclophosphamide, methotrexate, and fluorouracil (CMF) versus cyclophosphamide, doxorubicin, and fluorouracil (CAF) in node-negative breast cancer patients with and without tamoxifen (TAM), overall and by hormone receptor (HR) status.

PATIENTS AND METHODS

Node-negative patients identified by tumor size (> 2 cm), negative HR, or high S-phase fraction (n = 2,690) were randomly assigned to CMF, CAF, CMF + TAM (CMFT), or CAF + TAM (CAFT). Cox regression evaluated overall survival (OS) and disease-free survival (DFS) for CAF versus CMF and TAM versus no TAM separately. Two-sided CIs and one-sided P values for planned comparisons were calculated.

RESULTS

Ten-year estimates indicated that CAF was not significantly better than CMF (P = .13) for the primary outcome of DFS (77% v 75%; HR = 1.09; 95% CI, 0.94 to 1.27). CAF had slightly better OS than CMF (85% v 82%, HR = 1.19 for CMF v CAF; 95% CI, 0.99 to 1.43); values were statistically significant in the planned one-sided test (P = .03). Toxicity was greater with CAF and did not increase with TAM. Overall, TAM had no benefit (DFS, P = .16; OS, P = .37), but the TAM effect differed by HR groups. For HR-positive patients, TAM was beneficial (DFS, HR = 1.32 for no TAM v TAM; 95% CI, 1.09 to 1.61; P = .003; OS, HR = 1.26; 95% CI, 0.99 to 1.61; P = .03), but not for HR-negative patients (DFS, HR = 0.81 for no TAM v TAM; 95% CI, 0.64 to 1.03; OS, HR = 0.79; 95% CI, 0.60 to 1.05).

CONCLUSION

CAF did not improve DFS compared with CMF; there was a slight effect on OS. Given greater toxicity, we cannot conclude CAF to be superior to CMF. TAM is effective in HR-positive disease, but not in HR-negative disease.

Comparison of chemotherapy with chemohormonal therapy as first-line therapy for metastatic, hormone-sensitive breast cancer: An Eastern Cooperative Oncology Group study

PURPOSE

Although hormonal therapy represents standard therapy for metastatic hormone-sensitive disease, many patients receive initial chemotherapy because of the location, bulk, or aggressiveness of their disease. It is uncertain whether simultaneous hormonal therapy provides additional benefit compared with chemotherapy alone. Eastern Cooperative Oncology Group trial E3186 was initiated to explore this question.

PATIENTS AND METHODS

Between January 1988 and December 1992, 231 patients with estrogen receptor (ER)-positive or ER-unknown metastatic breast cancer were randomized to receive either chemotherapy (cyclophosphamide, doxorubicin, and fluorouracil ¿CAF) or chemohormonal therapy (CAF plus tamoxifen and Halotestin ¿fluoxymesterone; Pharmacia-Upjohn, Kalamazoo, MI ¿CAFTH) as front-line therapy for metastatic breast cancer. Patients who experienced a complete response to induction therapy either received or did not receive maintenance cyclophosphamide, methotrexate, fluorouracil, prednisone, and TH as a secondary randomization.

RESULTS

The response rates (complete response and partial response) of patients who received CAF and CAFTH were similar (69.2% v 68.9%, respectively; P =.99). Time to treatment failure (TTF) was slightly longer for patients who received chemohormonal therapy compared with chemotherapy alone patients (13.4 months v 10.3 months, respectively; P =.087), and TTF was significantly longer in ER-positive compared with ER-negative patients (17.4 months v 10.3 months, respectively; P =.048). However, ER status had no effect on overall survival (30.0 months for CAF v 29.3 months for CAFTH).

CONCLUSION

In patients with potentially hormone-sensitive metastatic breast cancer, chemohormonal therapy prolongs TTF for ER-positive patients without improving overall survival.

HER-2/neu in node-negative breast cancer: prognostic significance of overexpression influenced by the presence of in situ carcinoma

PURPOSE

Amplification and/or overexpression of the HER-2/neu oncogene have been shown to correlate with poor clinical outcome in patients with axillary node-positive breast cancer. In contrast, the prognostic significance of HER-2/neu in node-negative disease is controversial. This study was undertaken to evaluate further the relationship between HER-2/neu and clinical outcome in node-negative disease.

PATIENTS AND METHODS

Overexpression of HER-2/neu was evaluated by permanent-section immunohistochemistry in tumors from 613 patients with long-term clinical follow-up enrolled in the Intergroup Study 0011. Patients were stratified into low-risk (n = 307) and high-risk (n = 306) groups on the basis of tumor size and estrogen-receptor (ER) status. Low-risk patients were defined as having small (less than 3 cm), ER-positive tumors and were observed without additional treatment after initial surgery. High-risk patients had either ER-negative or large (greater than or equal to 3 cm), ER-positive tumors and were randomized to be observed (n = 146) or to receive adjuvant chemotherapy (n = 160) after surgery.

RESULTS

The rate of HER-2/neu overexpression was 14.3% in all tumors combined and was higher in invasive carcinomas with (21.5%) than without (11.2%) a significant noninvasive or in situ histologic component (P less than .0001). There was no relationship between overexpression and clinical outcome in the natural history setting of combined low-risk and high-risk patients not receiving adjuvant therapy (n = 453). Based on the reasoning that the influence of HER-2/neu may have been obscured by high-risk features and/or the presence of noninvasive carcinoma, we also analyzed the subset of patients with low-risk lesions not containing a significant in situ component (n = 179). Patients of this group with HER-2/neu-positive tumors showed only 40% disease-free survival (DFS) at 5 years, compared with over 80% in patients with HER-2/neu-negative tumors (P less than .0001). A similar inverse correlation was observed between overexpression and overall survival in the same group of patients (P = .0001). In a separate analysis involving patients receiving adjuvant chemotherapy, those with HER-2/neu-negative tumors showed significantly improved DFS in response to therapy compared with patients with HER-2/neu-positive tumors.

CONCLUSION

Overexpression of HER-2/neu is associated with poor clinical outcome in a subset of node-negative patients with small, ER-positive, predominantly invasive tumors and may play a role in resistance to adjuvant chemotherapy.

Therapy in premenopausal women with advanced, oestrogen positive or/and progesterone positive breast cancer: surgical oophorectomy versus the LHRH analogue, Zoladex

The basis and design of a trial that will compare surgical oophorectomy with the LHRH analogue, Zoladex, in the treatment of premenopausal women with advanced, oestrogen receptor-positive or progesterone receptor-positive breast cancer, is described.

Quantitative gas-liquid chromatography of neutral sugars in human serum glycoproteins. Fucose, mannose, and galactose as predictors in ovarian and small cell lung carcinoma

A precise and accurate gas-liquid chromatographic (GLC) method has been developed for the quantitative analysis of the neutral sugars L-fucose (6-deoxygalactose), mannose, galactose, and glucose in ethanol precipitates of human serum proteins. The chromatographic conditions and sample preparation resulted in short analysis time (20 min per run) and made routine analyses practicable (twelve samples per day). The alditol acetate derivatization yielded single derivatives for each sugar. Complete separation was achieved on a 2.0 m X 2 mm I.D. column with 2.0% Silar-7CP on Chromosorb W AW 80--100 mesh. The results of hydrolysis showed that the release of fucose and galactose preceded the release of mannose. Hydrolysis with AG 50 W-X8 (H+) ion-exchange resin in 0.5 N HCl at 100 degrees for 7 h optimized glycosidic bond cleavage with only minimal destruction of fucose, mannose and galactose. A combination of strong cation- and anion-exchange resin columns was used to remove chromatographic background of peptides, amino acids, amino sugars, and inorganic ions. An average R.S.D. of less than 4% with recovery of greater than 86% for the three sugars was achieved. The homogeneity of the chromatographic peaks for the neutral sugars of normal human serum glycoproteins was confirmed by GLC--mass spectrometry. Significantly elevated ratios of fucose, galactose, and mannose to serum protein were observed for patients with small cell lung and ovarian carcinomas.