Michael J. Swartz

Analysis of Fluorouracil-Based Adjuvant Chemotherapy and Radiation After Pancreaticoduodenectomy for Ductal Adenocarcinoma of the Pancreas: Results of a Large, Prospectively Collected Database at the Johns Hopkins Hospital

PURPOSE To examine the efficacy of adjuvant chemoradiotherapy after pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PC) in patients undergoing resection at Johns Hopkins Hospital (JHH; Baltimore, MD). PATIENTS AND METHODS Between August 30, 1993, and February 28, 2005, a total of 908 patients underwent PD for PC at JHH. A prospective database was reviewed to determine which patients received fluorouracil (FU) -based CRT. Excluded patients had metastatic disease, died 60 or fewer days after PD, received preoperative therapy, an experimental vaccine, adjuvant chemotherapy or radiation alone. The final cohort includes 616 patients. RESULTS The median follow-up was 17.8 months (interquartile range, 9.7 to 33.5 months). Overall median survival was 17.9 months (95% CI, 16.3 to 19.5 months). Groups were similar with respect to tumor size, nodal status, and margin status, but the CRT group was younger (P < .001), and less likely to present with a severe comorbid disease (P = .001). Patients with carcinomas larger than 3 cm (P = .001), grade 3 and 4 (P < .001), margin-positive resection (P = .001), and complications after surgery (P = .017) had poor long-term survival. Patients receiving CRT experienced an improved median (21.2 v 14.4 months; P < .001), 2-year (43.9% v 31.9%), and 5-year (20.1% v 15.4%) survival compared with no CRT. After controlling for high-risk features, CRT was still associated with improved survival (relative risk = 0.74; 95% CI, 0.62 to 0.89). CONCLUSION These data suggest that adjuvant concurrent FU-based CRT significantly improves survival after PD for PC when compared with patients not receiving CRT. These data support the use of combined adjuvant CRT for PC.

MUC4 Expression Increases Progressively in Pancreatic Intraepithelial Neoplasia

Pancreatic adenocarcinoma is believed to develop from histologically identifiable intraductal lesions known as pancreatic intraepithelial neoplasias (PanINs) that undergo a series of architectural, cytologic, and genetic changes, a progression model similar to the adenoma-carcinoma sequence in the colon. The apomucin MUC4 has been implicated in invasive pancreatic adenocarcinoma. MUC4 expression is not detectable at the RNA level in normal pancreas but is detectable at high levels in invasive pancreatic adenocarcinoma. We documented the pattern of expression of MUC4 in PanINs by studying a series of 71 PanIN lesions immunohistochemically using a new monoclonal antibody to MUC4. Five (17%) of 30 PanIN-1 lesions, 10 (36%) of 28 PanIN-2 lesions, 11 (85%) of 13 PanIN-3 lesions, and 25 (89%) of 28 invasive adenocarcinomas labeled with the MUC4 antibody used in the study. In addition, afew nonneoplastic lesions labeled with the MUC4 antibody, including reactive ducts in chronic pancreatitis, atrophic ducts filled with inspissated secretions, and ducts showing squamous metaplasia. Our data help establish the patterns of MUC4 expression in neoplastic precursors in the pancreas and add further support to the progression model for pancreatic adenocarcinoma.

In vivo Therapeutic Responses Contingent on Fanconi Anemia/BRCA2 Status of the Tumor

Purpose:BRCA2, FANCC, and FANCG gene mutations are present in a subset of pancreatic cancer. Defects in these genes could lead to hypersensitivity to interstrand cross-linkers in vivo and a more optimal treatment of pancreatic cancer patients based on the genetic profile of the tumor. Experimental Design: Two retrovirally complemented pancreatic cancer cell lines having defects in the Fanconi anemia pathway, PL11 (FANCC-mutated) and Hs766T (FANCG-mutated), as well as several parental pancreatic cancer cell lines with or without mutations in the Fanconi anemia/BRCA2 pathway, were assayed for in vitro and in vivo sensitivities to various chemotherapeutic agents. Results: A distinct dichotomy of drug responses was observed. Fanconi anemia–defective cancer cells were hypersensitive to the cross-linking agents mitomycin C (MMC), cisplatin, chlorambucil, and melphalan but not to 5-fluorouracil, gemcitabine, doxorubicin, etoposide, vinblastine, or paclitaxel. Hypersensitivity to cross-linking agents was confirmed in vivo; FANCC-deficient xenografts of PL11 and BRCA2-deficient xenografts of CAPAN1 regressed on treatment with two different regimens of MMC whereas Fanconi anemia–proficient xenografts did not. The MMC response comprised cell cycle arrest, apoptosis, and necrosis. Xenografts of PL11 also regressed after a single dose of cyclophosphamide whereas xenografts of genetically complemented PL11FANCC did not. Conclusions: MMC or other cross-linking agents as a clinical therapy for pancreatic cancer patients with tumors harboring defects in the Fanconi anemia/BRCA2 pathway should be specifically investigated.

P6D-2 Ultrasound Bone Segmentation Using Dynamic Programming

Segmentation of bone surface in ultrasound images has numerous applications in computer aided orthopedic surgery. A robust bone surface extraction technique for ultrasound images can be used to non-invasively probe the bone surface. In this work, we present early results with an intuitive and computationally inexpensive bone segmentation approach. The prior knowledge about the appearance of bone in ultrasound images is exploited toward achieving robust and fast bone segmentation. Continuity and smoothness of the bone surface are incorporated in a cost function, which is globally minimized using dynamic programming. The performance of this method is evaluated on ultrasound images collected from two male cadavers. The images are segmented in about half a second making the algorithm suitable for real-time applications. Comparison between manual and automatic segmentation shows an average accuracy of less than 3 pixels (0.3 mm).

Patterns of Recurrence Following Liver Resection for Colorectal Metastases: Effect of Primary Rectal Tumor Site

HYPOTHESIS Patients with rectal adenocarcinoma are at increased risk of locoregional recurrence compared with patients with colon cancer. This may affect the pattern of recurrence and survival rates following hepatic resection of liver metastases from rectal adenocarcinoma. DESIGN Retrospective review of a prospectively collected cancer center database. PATIENT AND METHODS From April 1, 1984, to December 31, 2005, 582 patients with liver metastases from a primary colorectal adenocarcinoma underwent hepatic resection. Clinical and pathological factors were analyzed using Cox regression analyses and log-rank tests. RESULTS Of 582 patients, 141 (24.2%) had liver metastases from a primary rectal tumor site. Treatment of the primary rectal tumor most frequently included chemoradiation therapy (59.6%) and low anterior resection (63.1%). Most rectal tumors were pathological stage T3/T4 (85.8%) and N1 (68.1%). Treatment directed at the hepatic metastases included resection only (81.5%), resection plus radiofrequency ablation (17.8%), or radiofrequency ablation only (0.7%). With a median follow-up time of 30.7 months, 80 of 141 patients (56.7%) developed recurrence; 23 patients (16.3%) developed recurrence in the pelvis. Of 23 patients with pelvic recurrence, 56.5% also developed recurrence in the liver. The 3- and 5-year survival rates for all patients were 62.4% and 36.4%, respectively. Of 80 patients who had a recurrence following hepatic metastectomy, 23 (28.8%) underwent another operation. Following repeat metastectomy, 3- and 5-year survival rates were 76.7% and 38.6%, respectively. CONCLUSIONS Following resection of hepatic rectal metastases, pelvic recurrence is relatively common, and most patients with pelvic recurrence will also develop recurrence in the liver. Surgery for recurrent disease following hepatic resection of rectal metastases is warranted among well-selected patients.

Adjuvant Chemoradiotherapy After Pancreatic Resection for Invasive Carcinoma Associated With Intraductal Papillary Mucinous Neoplasm of the Pancreas

PURPOSE Intraductal papillary mucinous neoplasms are mucin-producing cystic neoplasms of the pancreas. One-third are associated with invasive carcinoma. We examined the benefit of adjuvant chemoradiotherapy (CRT) for this cohort. METHODS AND MATERIALS Patients who had undergone pancreatic resection at Johns Hopkins Hospital between 1999 and 2004 were reviewed. Of these patients, 83 with a resected pancreatic mass were found to have an intraductal papillary mucinous neoplasm with invasive carcinoma, 70 of whom met inclusion criteria for the present analysis. RESULTS The median age at surgery was 68 years. The median tumor size was 3.3 cm, and invasive carcinoma was present at the margin in 16% of the patients. Of the 70 patients, 50% had metastases to the lymph nodes and 64% had Stage II disease. The median survival was 28.0 months, and 2- and 5-year survival rate was 57% and 45%, respectively. Of the 70 patients, 40 had undergone adjuvant CRT. Those receiving CRT were more likely to have lymph node metastases, perineural invasion, and Stage II-III disease. The 2-year survival rate after surgery with vs. without CRT was 55.8% vs. 59.3%, respectively (p = NS). Patients with lymph node metastases or positive surgical margins benefited significantly from CRT (p = .047 and p = .042, respectively). On multivariate analysis, adjuvant CRT was associated with improved survival, with a relative risk of 0.43 (95% confidence interval, 0.19-0.95; p = .044) after adjusting for major confounders. CONCLUSION Adjuvant CRT conferred a 57% decrease in the relative risk of mortality after pancreaticoduodenectomy for intraductal papillary mucinous neoplasms with an associated invasive component after adjusting for major confounders. Patients with lymph node metastases or positive margins appeared to particularly benefit from CRT after definitive surgery.

Resected pancreatic adenosquamous carcinoma: clinicopathologic review and evaluation of adjuvant chemotherapy and radiation in 38 patients

Pancreatic adenosquamous carcinoma is a rare morphological variant of pancreatic adenocarcinoma with an especially poor prognosis. The purpose of this study is to identify clinicopathologic features associated with prognosis, assess whether the percentage of squamous differentiation in pancreatic adenosquamous carcinoma is associated with an inferior prognosis, and examine the impact of adjuvant chemoradiation therapy on overall survival. Forty-five (1.2%) of 3651 patients who underwent pancreatic resection at the Johns Hopkins Hospital, Baltimore, MD, between 1986 and 2007 were identified with adenocarcinoma of the pancreas with any squamous differentiation. All pathologic specimens were re-reviewed. Statistical analyses were performed on the 38 patients amenable to adjuvant chemoradiation therapy for whom clinical outcome data could be obtained. Median age was 68 years (61% male). Sixty-one percent underwent pancreaticoduodenectomy. Median tumor size was 5.0 cm. Seventy-six percent of carcinomas were node positive, 37% were margin-positive resections, and 68% had 30% or more squamous differentiation. Median overall survival of the pancreatic adenosquamous carcinoma cohort was 10.9 months (range, 2.1-140.6 months; 95% confidence interval, 8.2-12.5 months). Adjuvant chemoradiation therapy was associated with superior overall survival in patients with pancreatic adenosquamous carcinoma (P = .005). Adjuvant chemoradiation therapy was associated with improved survival in patients with tumors 3 cm or larger and vascular or perineural invasion (P = .02, .03, .02, respectively). The proportion of squamous differentiation was not associated with median overall survival (< 30% versus > or = 30%, P = .82). Survival after pancreatic resection of pancreatic adenosquamous carcinoma is poor. Treatment with adjuvant chemoradiation therapy is associated with improved survival. The proportion of squamous differentiation in resected pancreatic adenosquamous carcinoma specimens does not appear to impact overall survival.

Hematopoietic Progenitor Stem Cell Homing in Mice Lethally Irradiated with Ionizing Radiation at Differing Dose Rates

Abstract Collis, S. J., Neutzel, S., Thompson, T. L., Swartz, M. J., Dillehay, L. E., Collector, M. I., Sharkis, S. J. and DeWeese, T. L. Hematopoietic Progenitor Stem Cell Homing in Mice Lethally Irradiated with Ionizing Radiation at Differing Dose Rates. Radiat. Res. 162, 48–55 (2004). It has recently been shown that specific lineage-depleted murine hematopoietic stem cells that home to the bone marrow 2 days after transplantation of ablated primary recipients are capable of long-term engraftment and repopulation of secondary recipients. We were interested in determining whether the rate at which the ablating radiation dose was delivered to the mice affected the homing of lineage-depleted stem cells to the bone marrow and/or sites of tissue damage. Fractionated, lineage-depleted donor marrow cells were isolated and labeled with the membrane dye PKH26. Recipient mice were lethally irradiated with 11 Gy ionizing radiation using varying dose rates and were immediately injected with PKH26-labeled progenitor stem cells. With the exception of the lowest dose-rate group, all irradiated mice had an approximately fivefold (P = 0.014 to 0.025) reduction in stem cell homing to the bone marrow compared to unirradiated control animals. A fivefold reduction of stem cell homing to the spleen compared to unirradiated animals was also observed, though this was not statistically significant for any dose-rate group (P = 0.072 to 0.233). This difference in homing could not be explained by increased stem cell apoptosis/necrosis or non-marrow tissue homing to the intestine, lung or liver. We show that the dose rate at which a lethal dose of total-body radiation is delivered does not augment hematopoietic progenitor stem cell homing to the bone marrow, spleen or sites of early radiation-mediated tissue damage at either 2 or 5 days postirradiation/transplantation. The observation that greater homing was seen in unirradiated control mice calls into question the concept that adequate bone marrow stem cell homing requires radiation-induced “space” to be made in the marrow, certainly for the enriched early progenitor hematopoietic stem cells used for this set of experiments. Further experiments will be needed to determine whether these homed cells are as capable of giving rise to long-term engraftment/repopulation of the marrow of secondary recipients as they are in irradiated recipients.

Outcomes of Adjuvant Chemoradiation After Pancreaticoduodenectomy With Mesenterico-Portal Vein Resection for Adenocarcinoma of the Pancreas

PURPOSE Surgery followed by chemotherapy and radiation (CRT) offers patients with pancreatic adenocarcinoma a chance for extended survival. In some patients, however, resection is difficult because of vascular involvement by the carcinoma, necessitating resection and grafting of the mesenterico-portal vessels. The purpose of this study was to compare outcomes between pancreaticoduodenectomy (PD) with and without mesenterico-portal vein resection (VR) in patients receiving adjuvant CRT for pancreatic adenocarcinoma. METHODS AND MATERIALS Between 1993 and 2005, 160 patients underwent PD with 5-FU-based adjuvant CRT followed by maintenance chemotherapy at the Johns Hopkins Hospital; 20 (12.5%) of the 160 underwent VR. Clinical outcomes, including median survival, overall survival, and complication rates were assessed for both groups. RESULTS Patients who underwent VR had significantly longer operative times (p = 0.009), greater intraoperative blood loss (p = 0.01), and longer postoperative lengths of stay (p = 0.03). However, postoperative morbidity, median survival, and overall survival rates were similar between the two groups. Most patients (70%) from both groups were able to complete CRT, and a subgroup analysis demonstrated no appreciable differences in terms of complications. None of the VR patients who received adjuvant CRT developed veno-oclusive disease or graft failure/leakage. CONCLUSION In a cohort of patients treated with adjuvant 5-FU-based CRT at the Johns Hopkins Hospital, having a VR at the time of PD resulted in similar complication rates and survival. These data support the feasibility and safety of adjuvant CRT in patients undergoing VR at the time of PD.