Karl C. Podratz

Activity of the Dual Kinase Inhibitor Lapatinib (GW572016) against HER-2-Overexpressing and Trastuzumab-Treated Breast Cancer Cells

Lapatinib (GW572016) is a selective inhibitor of both epidermal growth factor receptor (EGFR) and HER-2 tyrosine kinases. Here, we explore the therapeutic potential of lapatinib by testing its effect on tumor cell growth in a panel of 31 characterized human breast cancer cell lines, including trastuzumab-conditioned HER-2-positive cell lines. We further characterize its activity in combination with trastuzumab and analyze whether EGFR and HER-2 expression or changes induced in the activation of EGFR, HER-2, Raf, AKT, or extracellular signal-regulated kinase (ERK) are markers of drug activity. We report that concentration-dependent antiproliferative effects of lapatinib were seen in all breast cancer cell lines tested but varied significantly between individual cell lines with up to 1,000-fold difference in the IC(50)s (range, 0.010-18.6 micromol/L). Response to lapatinib was significantly correlated with HER-2 expression and its ability to inhibit HER-2, Raf, AKT, and ERK phosphorylation. Long-term in vivo lapatinib studies were conducted with human breast cancer xenografts in athymic mice. Treatment over 77 days resulted in a sustained and significant reduction in xenograft volume compared with untreated controls. For the combination of lapatinib plus trastuzumab, synergistic drug interactions were observed in four different HER-2-overexpressing cell lines. Moreover, lapatinib retained significant in vitro activity against cell lines selected for long-term outgrowth (>9 months) in trastuzumab-containing (100 microg/mL) culture medium. These observations provide a clear biological rationale to test lapatinib as a single agent or in combination with trastuzumab in HER-2-overexpressing breast cancer and in patients with clinical resistance to trastuzumab.

Prospective assessment of lymphatic dissemination in endometrial cancer: a paradigm shift in surgical staging.

OBJECTIVE To prospectively assess pelvic and para-aortic lymph node metastases in endometrial cancer with lymphatic dissemination, emphasizing the examination of para-aortic metastases relative to the inferior mesenteric artery (IMA). METHODS Over 36 months, 422 consecutive patients were managed by predefined surgical guidelines differentiating low-risk patients from patients at risk for dissemination requiring systematic lymphadenectomy. Low risk was defined as grade 1 or 2 endometrioid type with myometrial invasion (MI) < or = 50% and primary tumor diameter (PTD) < or = 2 cm. Pelvic and para-aortic lymph nodes were submitted separately, with nodes identified from all 8 pelvic and 4 para-aortic node-bearing basins. Surgical quality assessments examined median node counts (primary surrogate for quality) and nodes harvested above and below the IMA and excised gonadal veins (secondary surrogates). RESULTS Lymphadenectomy was not required in 27% of patients (all low risk) and in 33% (n=112) of endometrioid cases. However, 22 patients (20%) of this latter cohort had lymphadenectomy and all lymph nodes were negative. Sixty-three (22%) of 281 patients undergoing lymphadenectomy had lymph node metastases: both pelvic and para-aortic in 51%, only pelvic in 33%, and isolated to the para-aortic area in 16%. Therefore, 67% of patients with lymphatic dissemination had para-aortic lymph node metastases. Furthermore, 77% of patients with para-aortic node involvement had metastases above the IMA, whereas nodes in the ipsilateral para-aortic area below the IMA and ipsilateral common iliac basin were declared negative in 60% and 71%, respectively. Gonadal veins were excised in 25 patients with para-aortic node metastases; 7 patients (28%) had documented metastatic involvement of gonadal veins or surrounding soft tissue. CONCLUSIONS The high rate of lymphatic metastasis above the IMA indicates the need for systematic pelvic and para-aortic lymphadenectomy (vs sampling) up to the renal vessels. The latter should include consideration of excision of the gonadal veins. Conversely, lymphadenectomy does not benefit patients with grade 1 and 2 endometrioid lesions with MI < or = 50% and PTD < or = 2 cm.

Aggressive surgical effort and improved survival in advanced-stage ovarian cancer

OBJECTIVE: Residual disease after initial surgery for ovarian cancer is the strongest prognostic factor for survival. However, the extent of surgical resection required to achieve optimal cytoreduction is controversial. Our goal was to estimate the effect of aggressive surgical resection on ovarian cancer patient survival. METHODS: A retrospective cohort study of consecutive patients with International Federation of Gynecology and Obstetrics stage IIIC ovarian cancer undergoing primary surgery was conducted between January 1, 1994, and December 31, 1998. The main outcome measures were residual disease after cytoreduction, frequency of radical surgical resection, and 5-year disease-specific survival. RESULTS: The study comprised 194 patients, including 144 with carcinomatosis. The mean patient age and follow-up time were 64.4 and 3.5 years, respectively. After surgery, 131 (67.5%) of the 194 patients had less than 1 cm of residual disease (definition of optimal cytoreduction). Considering all patients, residual disease was the only independent predictor of survival; the need to perform radical procedures to achieve optimal cytoreduction was not associated with a decrease in survival. For the subgroup of patients with carcinomatosis, residual disease and the performance of radical surgical procedures were the only independent predictors. Disease-specific survival was markedly improved for patients with carcinomatosis operated on by surgeons who most frequently used radical procedures compared with those least likely to use radical procedures (44% versus 17%, P < .001). CONCLUSION: Overall, residual disease was the only independent predictor of survival. Minimizing residual disease through aggressive surgical resection was beneficial, especially in patients with carcinomatosis. LEVEL OF EVIDENCE: II-2

Preoperative evaluation of serum CA 125 levels in premenopausal and postmenopausal patients with pelvic masses. Discrimination of benign from malignant disease

CA 125 levels were measured in 158 patients with palpable pelvic masses who were about to undergo diagnostic laparotomy. When the 68 patients found to have cancer were compared with the 90 patients with benign disease, those with malignancies were significantly older, were more frequently postmenopausal, and had significantly higher values of serum CA 125. Patients with benign pelvic masses had CA 125 levels greater than 65 U/ml in 8% of cases, whereas those with malignancies had CA 125 levels greater than 65 U/ml in 75% of cases. If only those patients who had frankly malignant, primary, nonmucinous epithelial ovarian carcinomas were considered, CA 125 levels greater than 65 U/ml predicted malignancy with a sensitivity of 91% for all patients. Greater sensitivity and specificity were observed in the postmenopausal subgroup than in the premenopausal subgroup. In the postmenopausal group with a 63% prevalence of ovarian cancer the predictive positive value was 98% and the predictive value negative was 72%. In a premenopausal population with a 15% prevalence of ovarian cancer the predictive value for a positive test was 49%, while the predictive value for a negative test was 93%.

HER-2/neu expression: A major prognostic factor in endometrial cancer☆

The HER-2/neu oncogene encodes for a specific cell-surface glycoprotein similar to the human growth factor receptor. An analysis of 247 patients with endometrial cancer treated between 1979 and 1983 was performed using an immunoperoxidase technique on paraffin-embedded tissue samples to detect HER-2/neu overexpression. Specimens were graded blindly with regard to HER-2/neu staining intensity. Overexpression of HER-2/neu was identified as strong in 37 patients (15%), mild in 144 (58%), and none in 66 (27%). The 5-year progression-free survival was 56% for the strong, 83% for the mild, and 95% for the nonstaining groups. The strong (P < 0.0001) and the mild (P = 0.028) staining groups were distinct from the nonstaining group in predicting progression-free survival. Likewise, strong overexpression was associated with a poor (51%) overall survival (P < 0.0001). Multivariate analysis revealed that intense overexpression had independent significance in predicting progression-free (P = 0.0003) and overall survival (P < 0.0001). In stage I patients (203), the 5-year progression-free survival was 62% for the strong and 97% for the nonstaining groups (P = 0.0007). This retained independent significance when subjected to multivariate analysis (P = 0.0017). Other significant stage I prognostic factors in multivariate analysis included DNA ploidy, histologic subtype, and histologic grade but not depth of invasion.

Phase I Trial of Intraperitoneal Administration of an Oncolytic Measles Virus Strain Engineered to Express Carcinoembryonic Antigen for Recurrent Ovarian Cancer

Edmonston vaccine strains of measles virus (MV) have shown significant antitumor activity in preclinical models of ovarian cancer. We engineered MV to express the marker peptide carcinoembryonic antigen (MV-CEA virus) to also permit real-time monitoring of viral gene expression in tumors in the clinical setting. Patients with Taxol and platinum-refractory recurrent ovarian cancer and normal CEA levels were eligible for this phase I trial. Twenty-one patients were treated with MV-CEA i.p. every 4 weeks for up to 6 cycles at seven different dose levels (10(3)-10(9) TCID(50)). We observed no dose-limiting toxicity, treatment-induced immunosuppression, development of anti-CEA antibodies, increase in anti-MV antibody titers, or virus shedding in urine or saliva. Dose-dependent CEA elevation in peritoneal fluid and serum was observed. Immunohistochemical analysis of patient tumor specimens revealed overexpression of measles receptor CD46 in 13 of 15 patients. Best objective response was dose-dependent disease stabilization in 14 of 21 patients with a median duration of 92.5 days (range, 54-277 days). Five patients had significant decreases in CA-125 levels. Median survival of patients on study was 12.15 months (range, 1.3-38.4 months), comparing favorably to an expected median survival of 6 months in this patient population. Our findings indicate that i.p. administration of MV-CEA is well tolerated and results in dose-dependent biological activity in a cohort of heavily pretreated recurrent ovarian cancer patients.

Identification of prognostic factors and risk groups in patients found to have nodal metastasis at the time of radical hysterectomy for early-stage squamous carcinoma of the cervix☆

In a retrospective study conducted at the University of Alabama at Birmingham, the University of Michigan, and the Mayo Clinic, 185 patients with previously untreated FIGO stage IB and IIA squamous cell carcinoma of the cervix were found to have nodal metastasis at the time of radical hysterectomy and pelvic lymphadenectomy. Of these patients, 103 received adjuvant pelvic irradiation. Cancer recurred in 76 patients; the median time to recurrence was 3.1 years. The prognostic significance of patient age, clinical stage, lesion diameter, number and location of nodal metastases, and use of adjuvant radiation therapy was determined by multivariate analysis. Only patient age (P = 0.0006), lesion diameter (P less than 0.0001), and number of nodal metastases (P = 0.0004) were noted to be significant factors in determining overall survival. Rates of recurrence were also related to these factors. Employment of these significant variables led to identification of four risk groups. In general, patients with small cervical lesions (diameter less than 1 cm) and no more than two nodes with metastases fell into the low-risk category; those patients with large cervical lesions (diameter greater than 4 cm) and more than two involved nodes fell into the high-risk category. All other patients were categorized into intermediate-risk groups. Ten-year survival was 92% in the low-risk group (n = 13), 70% in the low-intermediate-risk group (n = 66), 56% in the high-intermediate-risk group (n = 66), and 13% in the high-risk group (n = 20). This risk group classification identifies subgroups of early-stage cervical carcinoma patients found to have nodal metastasis at the time of radical hysterectomy that warrant appropriately selected adjuvant therapy.

Prognostic significance of p53 immunostaining in epithelial ovarian cancer.

PURPOSE To evaluate the prognostic significance of p53 expression in epithelial ovarian cancer, including a subset of stage I patients, and to look for correlations between p53 expression and other disease parameters, including stage, grade, age, histologic subtype, second-look results, ploidy, and percent S phase. PATIENTS AND METHODS We analyzed p53 expression in 284 patients with epithelial ovarian cancer using immunohistochemical techniques in paraffin-embedded specimens. There were 36 patients with stage I disease, 20 with stage II disease, 186 with stage III disease, and 42 with stage IV disease. RESULTS p53 immunoreactivity was present in 177 cases (62%). p53 expression was associated with grade 3 to 4 disease (P = .003). The following factors were associated with a decrease in overall survival in a univarate analysis: stage III or IV disease (P = .0001), grade 3 or 4 disease (P = .0001), age above the median (P = .0002), and p53 reactivity (P = .04). In a multivariate analysis, stage, grade, and age retained independent prognostic significance. In the subset of 36 stage I patients, p53 positively approached statistical significance (P = .10) as a negative prognostic factor in a univariate analysis. CONCLUSION Abnormalities of p53 expression occur commonly in epithelial ovarian cancer. Although associated with decreased survival in a univariate analysis, this biologic marker did not retain independent prognostic significance in a multivariate analysis. p53 expression should be studied in a larger cohort of early-stage patients, where accurate prognostic information is needed to direct therapy.

Carcinoma of the vulva: Analysis of treatment failures

Continuous follow-up of 224 patients treated for primary invasive squamous cell carcinoma of the vulva in a 20-year period (1955 to 1975) at the Mayo Clinic resulted in the detection of recurrent (or persistent) neoplasia in 59 (26%). Rates of treatment failure increased with advancing stage of disease-from 14% for Stage I to 71% for Stage IV. The rate of local vulvar recurrence was 18%, which was about three times greater than the recurrence rates for the groin, pelvis, and distant sites. However, the 1- and 5-year survival rates of 73% and 50%, respectively, after vulvar recurrence were in sharp contrast to the corresponding rates of 34% and 10% for regional or distant recurrence. When 35 patients with central vulvar extension of disease were evaluated, groups at excessive risk for treatment failure (lesions 4 cm or larger inguinal node involvement, or both) were identified and modifications in conventional therapy applicable to these groups were considered.

Peripheral nerve and ureteral tolerance to intraoperative radiation therapy: clinical and dose-response analysis

Between April 1981 and July 1984, 51 patients received intraoperative radiation therapy (IORT) as a component of therapy for the management of primary or recurrent pelvic malignancies which were initially unresectable for cure. For these patients, curative surgical alternatives did not exist, or would have involved extensive procedures such as pelvic exenteration, distal sacrectomy, hemipelvectomy, or hemicorporectomy. The primary disease was colorectal in 38 patients. Treatment consisted of external beam radiation (range 3000 to 6890 cGy, median 5040 cGy), surgical debulking when feasible, and an intraoperative electron beam boost to the gross or microscopic residual disease (dose range 1000 to 2500 cGy, median 1750 cGy) utilizing 9-18 MeV electrons. The most common IORT associated toxicities were peripheral neuropathy and ureteral obstruction. None were life-threatening or fatal in severity. Of the 50 patients evaluable for neurotoxicity analysis, 16 (32%) developed peripheral neuropathy consisting of pain in 16 patients, numbness and tingling in 11, and weakness in 8. The pain, numbness and tingling resolved in about 40% of patients, while weakness resolved in only 1 of 8. Sixteen ureters were initially unobstructed by tumor at the time of IORT. Of these, 10 (63%) subsequently showed evidence of obstruction and hydronephrosis. The development of neurotoxicity was more common at IORT doses of 1500 cGy or more versus 1000 cGy. Ureteral obstruction with hydronephrosis occurred more frequently at IORT doses of 1250 cGy or more compared to 1000 cGy. There was no relationship between the likelihood of developing complications and the total external beam dose. The observed dependence of human nerve toxicity primarily on the IORT dose is consistent with data generated from animal experiments.