Michael Bouvet

Improved sentinel lymph node localization in patients with primary melanoma with the use of radiolabeled colloid

BACKGROUND The purpose of this study was to determine whether the sentinel lymph node (SLN) localization technique, which uses blue dye and 99mTc-labeled sulfur colloid, provides advantages over blue dye alone in the management of patients with stages I and II cutaneous melanoma. METHODS The records of 626 consecutive patients with melanoma who underwent lymphatic mapping and SLN biopsy between 1991 and 1997 at the M.D. Anderson Cancer Center were reviewed. Lymphatic mapping was performed with isosulfan blue dye alone (n = 252) or in combination with 99mTc-labeled sulfur colloid accompanied by a hand-held gamma probe (n = 374). SLNs were defined as those that stained blue or demonstrated increased focal radiotracer uptake. RESULTS SLN identification rates improved from 87% (dye alone) to 99% (dye and colloid) (P < .0001) with the combined technique in all anatomic sites examined. The mean number of SLNs harvested from each basin was significantly greater in the patients mapped with dye and colloid (1.74 vs 1.31; P < .0001). Occult metastatic disease was identified in 17.5% of all patients and did not significantly differ between groups. In 92% of patients who had at least one positive SLN and were mapped with both agents, lymphatic metastases were identified in the SLN that contained the greatest radiotracer uptake. CONCLUSIONS SLN identification is enhanced by the addition of radiolabeled sulfur colloid and intraoperative use of the hand-held gamma probe and may identify SLNs missed by the blue dye alone. These data support the combined use of radiolabeled sulfur colloid and blue dye in lymphatic mapping procedures to improve the nodal staging of stages I and II melanoma.

Adenovirus-mediated wild-type p53 tumor suppressor gene therapy induces apoptosis and suppresses growth of human pancreatic cancer

AbstractBackground: Thep53 tumor suppressor gene is mutated in up to 70% of pancreatic adenocarcinomas. We determined the effect of reintroduction of the wild-typep53 gene on proliferation and apoptosis in human pancreatic cancer cells using an adenoviral vector containing the wild-typep53 tumor suppressor gene. Methods: Transduction efficiencies of six p53-mutant pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, CFPAC-1, MIA PaCa-2, and PANC-1) were determined using the reporter gene construct Ad5/CMV/β-gal. Cell proliferation was monitored using a3H-thymidine incorporation assay, Western blot analysis forp53 expression was performed, and DNA laddering and fluorescence-activated cell sorter analysis were used to assess apoptosis.p53 gene therapy was tested in vivo in a subcutaneous tumor model. Results: The cell lines varied in transduction efficiency. The MIA PaCa-2 cells had the highest transduction efficiency, with 65% of pancreatic tumor cells staining positive for beta-galactosidase (β-gal) at a multiplicity of infection (MOI) of 50. At the same MOI, only 15% of the CFPAC-1 cells expressed the β-gal gene. Adenovirus-mediatedp53 gene transfer suppressed growth of all human pancreatic cancer cell lines in a dose-dependent manner. Western blot analysis confirmed the presence of the p53 protein product at 48 hours after infection. DNA ladders demonstrated increased chromatin degradation, and fluorescence-activated cell sorter analysis demonstrated a four-fold increase in apoptotic cells at 48 and 72 hours following infection with Ad5/CMV/p53 in the MIA PaCa-2 and PANC-1 cells. Suppression of tumor growth mediated by induction of apoptosis was observed in vivo in an established nude mouse subcutaneous tumor model following intratumoral injections of Ad5/CMV/p53. Conclusions: Introduction of the wild-typep53 gene using an adenoviral vector in pancreatic cancer withp53 mutations induces apoptosis and inhibits cell growth. These data provide preliminary support for adenoviral mediatedp53 tumor suppressor gene therapy of human pancreatic cancer.

Clinical, pathologic, and economic parameters of laparoscopic colon resection for cancer

BACKGROUND The appropriateness of laparoscopic colon resection (LCR) as treatment for malignancy has been questioned. METHODS From 1992 to 1997, 91 patients were entered into a prospective study of LCR for cancer. Clinical, pathologic, and economic parameters of LCR were compared in a cohort of patients matched for age, tumor stage, and type of colectomy who underwent open colon resection (OCR) during the same time period. RESULTS With a median follow-up of 26 months, there were no significant differences in survival rate for patients in the LCR, converted colon resection, and OCR groups. There were no port-site recurrences and the number of lymph nodes harvested was similar among the procedures. Hospital stay was significantly shorter if laparoscopic resection was successful. Total hospital costs were similar for LCR and OCR; however, the costs were significantly higher for converted colon resection. CONCLUSIONS LCR is a sound oncologic procedure that can be performed with costs similar to OCR.

Hemangiopericytoma: A 20-year single-institution experience

AbstractBackground: Hemangiopericytoma is an uncommon soft tissue sarcoma. We sought to evaluate the long-term outcome of a consecutively treated patient cohort with hemangiopericytoma. Methods: The study involved 36 adult patients (older than 16 years) with hemangiopericytoma treated at The University of Texas M. D. Anderson Cancer Center between July 1975 and July 1995. Data on clinicopathologic parameters, surgical treatment, adjuvant therapy, disease recurrence, and survival were obtained from a review of medical records. Results: The median follow-up was 57 months. Twenty-eight patients (78%) underwent complete and potentially curative resection of their primary disease. Of the nine patients (32%) who had local recurrences, four (57%) had epidural tumors and three (43%) had retroperitoneal tumors, but none had extremity tumors. Extremity tumors were associated with a significantly prolonged local recurrence-free survival compared to tumors at nonextremity anatomic sites (P<.05). Ten patients had recurrences at distant sites. Of the 13 patients who experienced any form of disease recurrence, four had recurrences after a disease-free interval of more than 5 years. The 5-year actuarial survival rate for the entire group of 36 patients was 71%. Noncurative surgical treatment (P=.007) and development of distant metastatic disease (P=.013) were associated with shortened survival. Conclusion: Extended survival is common in hemangiopericytoma patients treated with curative intent. However, local and distant recurrences may occur after a prolonged disease-free interval, emphasizing the need for long-term follow-up. Retroperitoneal and meningeal tumors were associated with higher local recurrence rates; therefore, adjuvant therapies should be considered and evaluated for tumors at these sites.

Suppression of the immune response to an adenovirus vector and enhancement of intratumoral transgene expression by low-dose etoposide

Adenoviral vectors are commonly used in gene therapy trials because of their efficiency in gene transfer. However, their use is limited by cellular and humoral immune responses that result in temporary transgene expression and reduced efficacy of repeated vector administration. We hypothesized that certain oncolytic agents commonly used to treat cancer patients could suppress the immune response to adenoviral vectors, and enable repeated adenovirus- mediated cancer gene therapy. Etoposide and cyclophosphamide were tested for their ability to suppress the humoral and cellular immune responses to an adenoviral vector in immunocompetent C3H mice. Intratumoral transgene expression was monitored in adenovirus- immunized animals treated with etoposide or cyclophosphamide. Neutralizing antibodies to adenovirus and cytotoxic T lymphocyte (CTL) lysis of virally transduced cells were significantly suppressed in mice treated with etoposide at 2 or 10 mg/kg/day or cyclophosphamide at 10 mg/kg/day compared with untreated mice (P < 0.05). significantly larger areas of gene transduction were observed in treated animals compared with untreated mice or the mice treated with cyclophosphamide at 2 mg/kg/day (p < 0.05). our results suggest that repeated adenovirally mediated gene therapy is achievable in cancer patients who are concurrently undergoing treatment with chemotherapy.

Predictors of recurrence after local excision and postoperative chemoradiation therapy of adenocarcinoma of the rectum

Background: Local excision of rectal cancer preserves anal continence, bladder function, and normal sexual function. However, local recurrence after excision remains a significant problem. To further define the indications for local excision, we analyzed possible factors predictive of recurrence after local excision of rectal cancer.Methods: The charts of all patients undergoing local excision of adenocarcinoma of the rectum between 1985 and 1995 at a single institution were reviewed. Patients with metastatic disease at the time of excision and patients treated preoperatively with chemoradiation therapy were excluded. All available slides were reviewed by a single pathologist, who assessed the depth of invasion; the presence or absence of vascular invasion, lymphatic invasion, perineural invasion, and lymphocytic infiltrate; the mucinous status; and the degree of differentiation. Using the log-rank test and Cox proportional hazards model, univariate and multivariate analyses were performed to identify predictors of recurrence.Results: Ninety patients underwent local excision, 46 transanally and 44 using a Kraske approach. The breakdown of patients by tumor stage was as follows: Tis, 13%; T1, 41%; T2, 30%; T3, 15%; and Tx, 1%. Sixty-eight percent of patients with T1 tumors were treated with postoperative radiotherapy; all patients with T2 or T3 tumors were treated postoperatively with or without 5-fluorouracil. The median duration of follow-up was 51 months. The median tumor diameter was 2.5 cm (range, 0.4 to 7 cm), and the median distance of the tumor from the anal verge was 4.5 cm (range, 1 to 10 cm). The 4-year actuarial local disease-free survival rate broken down by tumor stage was as follows: Tis, 100%; T1, 95%; T2, 80%; and T3, 73%. The median time to local recurrence was 23 months (range, 7 to 61 months). Multivariate analysis showed that only tumor stage and margin status were predictors of local recurrence.Conclusions: Local excision and postoperative radiotherapy result in adequate local control of early stage (Tis and T1) adenocarcinoma of the rectum. Higher rates of recurrence were seen in patients with T2 and T3 tumors, especially in those with positive margins.

Primary pancreatic lymphoma

BACKGROUND Primary pancreatic lymphoma is a rare neoplasm that may be confused with pancreatic adenocarcinoma. We reviewed retrospectively our contemporary experience with this disease to define more clearly the clinical presentation of this disease and the proper role for percutaneous fine-needle aspiration biopsy and surgery. METHODS From 1980 to 1995, 11 patients with primary pancreatic lymphoma were treated at The University of Texas M. D. Anderson Cancer Center. Patient demographics, radiographic studies, fine-needle aspiration biopsy findings, operative procedures, and other treatment data were reviewed. RESULTS The median age of the 11 patients was 64 years (range, 37 to 74 years). Abdominal pain was the most common symptom at presentation. Five patients had an elevated lactate dehydrogenase level, and only two patients had hyperbilirubinemia. Computed tomography scan demonstrated encasement of the superior mesenteric artery or superior mesenteric-portal vein confluence in six patients. Seven patients underwent computed tomography-guided fine-needle aspiration; five had findings of lymphoma. Two patients underwent distal pancreatectomy and splenectomy, and one underwent pancreaticoduodenectomy. All patients were treated with combination chemotherapy, and seven received radiotherapy. Only two patients have died of disease (12 and 16 months after diagnosis) at a median follow-up time of 67 months. CONCLUSIONS In the majority of patients, pancreatic lymphoma can be distinguished from pancreatic adenocarcinoma on the basis of symptoms, laboratory and radiographic findings, and fine-needle aspiration biopsy results. Once the diagnosis is established, all patients should undergo systemic chemotherapy followed by involved-field radiotherapy if the tumor has not been resected.

Role of conservation therapy for invasive lobular carcinoma of the breast

AbstractBackground: Invasive lobular carcinoma (ILC) accounts for 5% to 10% of all invasive breast cancers. Although breast conservation therapy using local excision and postoperative irradiation is a standard therapy for early invasive ductal breast cancer, the result of this strategy in ILC is not well documented. We sought to determine the rate of locoregional recurrence after breast conservation therapy in patients with ILC. Methods: A retrospective review of 74 patients with ILC treated with breast conservation therapy at The University of Texas M. D. Anderson Cancer Center (n=43) or The John Wayne Cancer Institute (n=31) between 1977 and 1993 was performed. Results: The median age of patients was 60 years, and median follow-up was 56 months (range 1 to 207 months). Thirty-nine patients had American Joint Committee on Cancer stage I disease, 30 had stage IIa disease, and five had stage IIb disease. All patients underwent surgical resection and postoperative radiation therapy. Twelve patients received postoperative adjuvant chemotherapy, and 27 patients were treated with adjuvant hormonal therapy. The 5-year actuarial locoregional recurrence rate was 9.8%, and the median time to recurrence was 77 months (range 41 to 113 months). Patients with positive or close (⩽1 mm) surgical margins were at increased risk for local recurrence on univariate analysis (p=0.034). Of the nine patients with breast recurrence, six underwent salvage therapy with total mastectomy and are disease free at the time of this writing, two patients died of distant disease, and one is alive with local disease at the time of this report. The 5-year disease-specific survival rate was 93.7%. Conclusions: Breast conservation therapy for ILC achieves locoregional control in the majority of patients. However, long-term follow-up of patients is important because many local recurrences following breast conservation therapy are late events.

Reduced toxicity, attenuated immunogenicity and efficient mediation of human p53 gene expression in vivo by an adenovirus vector with deleted E1-E3 and inactivated E4 by GAL4-TATA promoter replacement.

A recombinant adenovirus with deleted E1 and E3, and E4-inactivated by replacing the E4 promoter with a synthetic promoter composed of a minimal TATA box and five consensus yeast GAL4-binding site elements was developed and used to express the human tumor suppresser gene p53. The toxicity and immunogenicity of this vector and vector-mediated p53 gene expression in vivo were studied in immunocompetent C3H and C57BL/6 mice. Expression of the late viral gene product, hexon protein, was observed in C3H and C57BL/6 mice injected with E4 wild-type adenovirus constructs Adv-cmv-β-Gal (BG), Adv-cmv-hp53 (WT), and empty E1− vector Adv-E4 (EW) 3 to 28 days after injection, but was undetectable in mice treated with E4 modified empty E1− vector Adv-GAL4 (EG) or Adv-cmv-hp53-GAL4 (G4). Expression of the p53 gene was observed in both WT- and G4-injected C3H and C57BL/6 mouse livers from days 3 to 28. Ten weeks after injection, p53 gene expression was still detected in G4-treated C57BL/6 mice at similar levels, but was not detectable in WT-treated mice. Vector-induced liver toxicity was evaluated by analyzing serum transaminases (SGOT and SGPT) activities. In all cases, SGOT and SGPT activities were markedly decreased in EG-treated C3H and C57BL/6 mice compared with those in EW-treated mice on days 3, 7 and 14 after injection. In C57BL/6 mice, the total anti-adenoviral CTL activities were two- to three-fold higher in animals treated with EW vector than in those treated with EG vector. These results suggest that inactivation of the E4 promoter efficiently diminished the viral replication and the late viral gene expression, reduced host immune response and consequently reduced toxicity and prolonged the duration of transgene expression in vivo.

Gene therapy and pancreatic cancer.

Adenocarcinoma of the pancreas is associated with a short survival due to frequent delays in diagnosis and the lack of effective systemic therapies. Advances in understanding the molecular basis of pancreatic cancer have allowed identification of molecular targets which are amenable to therapeutic intervention. Such targets include p53, K-ras, p16, and DPC-4. Gene therapy involves the transfer of genetic constructs which alter the neoplastic potential of the cancer cell. Vectors used in gene transfer include viral and non-viral methods. Presently, gene therapy of pancreatic cancer is limited to pre-clinical studies using in vitro and in vivo models. However, the initial results from these pre-clinical studies have been encouraging and will form the basis for clinical studies of gene transfer in patients with pancreatic cancer.