Philip B. Paty

Simultaneous liver and colorectal resections are safe for synchronous colorectal liver metastasis

BACKGROUND The optimal surgical strategy for the treatment of synchronous resectable colorectal liver metastasis has not been defined. The aims of this study were to review our experience with synchronous colorectal metastasis and to define the safety of simultaneous versus staged resection of the colon and liver. STUDY DESIGN From September 1984 through November 2001, 240 patients were treated surgically for primary adenocarcinoma of the large bowel and synchronous hepatic metastasis. Clinicopathologic, operative, and perioperative data were reviewed to evaluate selection criteria, operative methods, and perioperative outcomes. RESULTS One hundred thirty-four patients underwent simultaneous resection of a colorectal primary and hepatic metastasis in a single operation (Group I), and 106 patients underwent staged operations (Group II). Simultaneous resections tend to be performed for right colon primaries (p < 0.001), smaller (p < 0.01) and fewer (p < 0.001) liver metastases, and less extensive liver resection (p < 0.001). Complications were less common in the simultaneous resection group, with 65 patients (49%) sustaining 142 complications, compared with 71 patients (67%) sustaining 197 complications for both hospitalizations in the staged resection group (p < 0.003). Patients having simultaneous resection required fewer days in the hospital (median 10 days versus 18 days, p = 0.001). Perioperative mortality was similar (simultaneous, n = 3; staged, n = 3). CONCLUSIONS Simultaneous colon and liver resection is safe and efficient in the treatment of patients with colorectal cancer and synchronous liver metastasis. By avoiding a second laparotomy, the overall complication rate is reduced, with no change in operative mortality. Given its reduced morbidity, shorter treatment time, and similar cancer outcomes, simultaneous resection should be considered a safe option in patients with resectable synchronous colorectal metastasis.

Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

Objective:Our aims were to (1) determine the long-term oncologic outcome for patients with rectal cancer treated with preoperative combined modality therapy (CMT) followed by total mesorectal excision (TME), (2) identify factors predictive of oncologic outcome, and (3) determine the oncologic significance of the extent of pathologic tumor response. Summary Background Data:Locally advanced (T3–4 and/or N1) rectal adenocarcinoma is commonly treated with preoperative CMT and TME. However, the long-term oncologic results of this approach and factors predictive of a durable outcome remain largely unknown. Methods:Two hundred ninety-seven consecutive patients with locally advanced rectal adenocarcinoma at a median distance of 6cm from the anal verge (range 0–15 cm) were treated with preoperative CMT (radiation: 5040 centi-Gray (cGy) and 5-fluorouracil (5-FU)-based chemotherapy) followed by TME from 1988 to 2002. A prospectively collected database was queried for long-term oncologic outcome and predictive clinicopathologic factors. Results:With a median follow-up of 44 months, the estimated 10-year overall survival (OS) was 58% and 10 year recurrence-free survival (RFS) was 62%. On multivariate analysis, pathologic response >95%, lymphovascular invasion and/or perineural invasion (PNI), and positive lymph nodes were significantly associated with OS and RFS. Patients with a >95% pathologic response had a significantly improved OS (P = 0.003) and RFS (P = 0.002). Conclusions:Treatment of locally advanced rectal cancer with preoperative CMT followed by TME can provide for a durable 10-year OS of 58% and RFS of 62%. Patients who achieve a >95% response to preoperative CMT have an improved long-term oncologic outcome, a novel finding that deserves further study.

Long-term results of local excision for rectal cancer

ObjectiveTo review the authors’ experience with local excision of early rectal cancers to assess the effectiveness of initial treatment and of salvage surgery. Summary Background DataLocal excision for rectal cancer is appealing for its low morbidity and excellent functional results. However, its use is limited by inability to assess regional lymph nodes and uncertainty of oncologic outcome. MethodsPatients with T1 and T2 adenocarcinomas of the rectum treated by local excision as definitive surgery between 1969 to 1996 at the authors’ institution were reviewed. Pathology slides were reviewed. Among 125 assessable patients, 74 were T1 and 51 were T2. Thirty-one patients (25%) were selected to receive adjuvant radiation therapy. Fifteen of these 31 patients received adjuvant radiation in combination with 5-fluorouracil chemotherapy. Median follow-up was 6.7 years. One hundred fifteen patients (92%) were followed until death or for greater than 5 years, and 69 patients (55%) were followed until death or for greater than 10 years. Recurrence was recorded as local, distant, and overall. Survival was disease-specific. ResultsTen-year local recurrence and survival rates were 17% and 74% for T1 rectal cancers and 26% and 72% for T2 cancers. Median time to relapse was 1.4 years (range 0.4–7.0) for local recurrence and 2.5 years (0.8–7.5) for distant recurrence. In patients receiving radiotherapy, local recurrence was delayed (median 2.1 years vs. 1.1 years), but overall rates of local and overall recurrence and survival rates were similar to patients not receiving radiotherapy. Among 26 cancer deaths, 8 (28%) occurred more than 5 years after local excision. On multivariate analysis, no clinical or pathologic features were predictive of local recurrence. Intratumoral vascular invasion was the only significant predictor of survival. Among 34 patients who developed tumor recurrence, the pattern of first clinical recurrence was predominantly local: 50% local only, 18% local and distant, and 32% distant only. Among the 17 patients with isolated local recurrence, 14 underwent salvage resection. Actuarial survival among these surgically salvaged patients was 30% at 6 years after salvage. ConclusionsThe long-term risk of recurrence after local excision of T1 and T2 rectal cancers is substantial. Two thirds of patients with tumor recurrence have local failure, implicating inadequate resection in treatment failure. In this study, neither adjuvant radiotherapy nor salvage surgery was reliable in preventing or controlling local recurrence. The postoperative interval to cancer death is as long as 10 years, raising concern that cancer mortality may be higher than is generally appreciated. Additional treatment strategies are needed to improve the outcome of local excision.

PRELIMINARY RESULTS OF PREOPERATIVE 5-FLUOROURACIL, LOW-DOSE LEUCOVORIN, AND CONCURRENT RADIATION THERAPY FOR CLINICALLY RESECTABLE T3 RECTAL CANCER

PURPOSE: We report the downstaging, sphincter preservation, acute toxicity, and preliminary local control and survival results of preoperative 5-fiuorouracil (5-FU), low-dose leucovorin (LV), and concurrent radiation therapy followed by postoperative LV/5-FU for treatment of patients with clinically resectable T3 rectal cancer. MATERIALS AND METHODS: A total of 32 patients received two monthly cycles of preoperative LV/5-FU (bolus daily×5). Radiation therapy (5,040 cGy) began concurrently on day 1. Postoperatively, patients received a median of two monthly cycles of LV/5-FU (range, 0–10). RESULTS: The complete response rate was 9 percent pathologic and 13 percent clinical, for a total of 22 percent. Total Grade 3+ acute toxicity during the preoperative combined modality segment was 25 percent (8/32). Of the 20 patients who were thought to initially require an abdominoperineal resection and for whom the intent of treatment was sphincter preservation, 17 (85 percent) were able to undergo sphincter-preserving surgery. With a median follow-up of 22 (3–59) months, none have developed local failure, and the three-year actuarial diseasefree survival rate was 60 percent. CONCLUSION: Our data reveal encouraging downstaging, sphincter preservation, and acute toxicity with this regimen. Additional follow-up is needed to assess the long-term local control and survival rates.

Long-Term Prognostic Significance of Extent of Rectal Cancer Response to Preoperative Radiation and Chemotherapy

ObjectiveTo determine whether selected clinicopathologic factors, including the extent of pathologic response to preoperative radiation and chemotherapy (RT ± chemo), have an impact on long-term recurrence-free survival (RFS) in patients with locally advanced primary rectal cancer after optimal multimodality therapy. Summary Background DataAlthough complete pathologic response to preoperative RT ± chemo has been detected in up to 30% of rectal cancers, its significance on long-term outcome has not been widely reported. Previous retrospective studies evaluating clinical outcome in patients with complete or near-complete pathologic response documented good prognosis in this population but were limited by median follow-up in the range of 2 to 3 years. MethodsSixty-nine patients with locally advanced (T3–4 and/or N1) primary rectal cancer were prospectively identified. All were treated at one institution with preoperative RT to the pelvis (at least 4,500 cGy). Forty patients received concurrent preoperative 5-fluorouracil-based chemotherapy and 27 received both pre- and postoperative chemotherapy. Patients underwent resection 4 to 7 weeks after completion of RT. TNM stage, angiolymphatic or perineural invasion, and extent of response to preoperative RT ± chemo were determined by pathologic evaluation. Adverse pathologic features were defined as the presence of angiolymphatic and/or perineural invasion. RFS at 5 years was determined by the Kaplan-Meier method. ResultsWith a median follow-up of 69 months, 5-year RFS was 79%. RFS was significantly worse for patients with aggressive pathologic features and positive nodal status identified in the postirradiated surgical specimen. Risk ratios for RFS were 3.68 for the presence of aggressive pathologic features and 4.64 for node-positive rectal cancers. In patients with greater than 95% rectal cancer response to preoperative RT ± chemo, only one patient has died as a consequence of cancer, another has died of an unrelated cause, and the remainder were free of disease with a minimum follow-up of 47 months. ConclusionsThese data suggest that a marked response to preoperative RT ± chemo may be associated with good long-term outcome but was not predictive of RFS. The presence of poor histopathologic features and positive nodal status are the most important prognostic indicators after neoadjuvant therapy.

Elective bowel resection for incurable stage IV colorectal cancer: prognostic variables for asymptomatic patients

BACKGROUND Surgical resection of primary colorectal cancer (CRC) in patients with stage IV disease at initial presentation remains controversial. Although bowel resection to manage symptoms such as bleeding, perforation, or obstruction has been advocated, management of asymptomatic patients has not been well defined. Patient-dependent factors (performance status, comorbid disease) and extent of distant metastases are among the considerations that impact on the decision to proceed with surgical management in asymptomatic stage IV CRC patients. We postulated that selected patients might benefit from elective resection of the asymptomatic primary CRC. The extent of distant metastases was objectively measured by several methods to identify potential prognostic variables that may help guide patient selection in this population. STUDY DESIGN We reviewed hospital and colorectal service databases for the years 1996 to 1999. Stage IV patients who had colorectal resections with gross residual metastatic disease were identified (n = 209). Among these 209 patients, 82 patients operated on for symptoms (obstruction, perforation, bleeding, or pain) were excluded, leaving 127 patients who underwent elective resection of their asymptomatic primary CRC. Over the same time period, 103 stage IV patients who did not undergo resection were identified. Data on patient characteristics and clinical management were collected. A radiologist performed an independent review of available CT scans to assess extent of liver disease. The chi-square test was used for analysis of categoric data and Students t-test for continuous variables. Survival was determined by the Kaplan-Meier method and distributions compared by the log rank test. Multivariate analysis was performed using Cox regression. RESULTS The resected group could be easily distinguished from the nonresected group by a higher frequency of right colon cancers (p = 0.03) and metastatic disease restricted to the liver (p = 0.02) or one other site apart from the primary tumor (p = 0.02). Resected patients had prolonged median (16 versus 9 months, p < 0.001) and 2-year (25% versus 6%, p < 0.001) survival compared with patients never resected. Univariate analysis identified three significant prognostic variables (number of distant sites involved, metastases to liver only, and volume of hepatic replacement by tumor) in the resected group. Volume of hepatic replacement was also a significant predictor of survival in Cox multivariate regression analysis (p = 0.01). Subsequent to resection of asymptomatic primary CRC, 26 patients (20%) developed postoperative complications. Median hospital stay was 6 days. Two patients (1.6%) died within 30 days of surgery. CONCLUSION Stage IV patients selected for elective palliative resection of asymptomatic primary colorectal cancers had substantial postoperative survival that was significantly better than those never having resection. Limited metastatic tumor burden and less extensive liver involvement were associated with better survival and a higher likelihood of benefit from elective bowel resection in asymptomatic patients with incurable stage IV CRC.

Somatic mutations of the Parkinson's disease–associated gene PARK2 in glioblastoma and other human malignancies

Mutation of the gene PARK2, which encodes an E3 ubiquitin ligase, is the most common cause of early-onset Parkinsons disease. In a search for multisite tumor suppressors, we identified PARK2 as a frequently targeted gene on chromosome 6q25.2–q27 in cancer. Here we describe inactivating somatic mutations and frequent intragenic deletions of PARK2 in human malignancies. The PARK2 mutations in cancer occur in the same domains, and sometimes at the same residues, as the germline mutations causing familial Parkinsons disease. Cancer-specific mutations abrogate the growth-suppressive effects of the PARK2 protein. PARK2 mutations in cancer decrease PARK2s E3 ligase activity, compromising its ability to ubiquitinate cyclin E and resulting in mitotic instability. These data strongly point to PARK2 as a tumor suppressor on 6q25.2–q27. Thus, PARK2, a gene that causes neuronal dysfunction when mutated in the germline, may instead contribute to oncogenesis when altered in non-neuronal somatic cells.

Relationship of Gene Expression and Chromosomal Abnormalities in Colorectal Cancer

Several studies have verified the existence of multiple chromosomal abnormalities in colon cancer. However, the relationships between DNA copy number and gene expression have not been adequately explored nor globally monitored during the progression of the disease. In this work, three types of array-generated data (expression, single nucleotide polymorphism, and comparative genomic hybridization) were collected from a large set of colon cancer patients at various stages of the disease. Probes were annotated to specific chromosomal locations and coordinated alterations in DNA copy number and transcription levels were revealed at specific positions. We show that across many large regions of the genome, changes in expression level are correlated with alterations in DNA content. Often, large chromosomal segments, containing multiple genes, are transcriptionally affected in a coordinated way, and we show that the underlying mechanism is a corresponding change in DNA content. This implies that whereas specific chromosomal abnormalities may arise stochastically, the associated changes in expression of some or all of the affected genes are responsible for selecting cells bearing these abnormalities for clonal expansion. Indeed, particular chromosomal regions are frequently gained and overexpressed (e.g., 7p, 8q, 13q, and 20q) or lost and underexpressed (e.g., 1p, 4, 5q, 8p, 14q, 15q, and 18) in primary colon tumors, making it likely that these changes favor tumorigenicity. Furthermore, we show that these aberrations are absent in normal colon mucosa, appear in benign adenomas (albeit only in a small fraction of the samples), become more frequent as disease advances, and are found in the majority of metastatic samples.

Rate of Pathologic Complete Response with Increased Interval between Preoperative Combined Modality Therapy and Rectal Cancer Resection

INTRODUCTIONRecent data suggest a favorable prognosis for rectal cancer patients with a pathologic complete response to preoperative combined modality therapy. Prolongation of the interval between preoperative combined modality therapy and surgery (RT-surgery interval) as a means of increasing pathologic complete response rate has not been fully examined.METHODSOne hundred and fifty-five rectal cancer patients undergoing preoperative pelvic external beam radiation therapy and 5-fluorouracil-based chemotherapy followed by rectal resection were identified. All patients had endorectal ultrasound prior to combined modality therapy. Final pathology reports were reviewed for ypT and ypN stage and margin status. Medical records were reviewed for sphincter preservation, operative time, estimated blood loss, hospital stay, and morbidity (overall, anastomotic, and perineal).RESULTSA pathologic complete response (ypT0N0) occurred in 24 patients (15 percent). Median RT-surgery interval was 44 (range, 15-206) days. A pathologic complete response occurred in 19 percent of patients with an interval >44 days, vs. 12 percent in those with an interval ≤44 days (P = 0.27). Downstaging by three stages occurred more frequently in the long-interval group (15 percent vs. 6 percent, P = 0.11). The rates of sphincter preservation, positive margins, estimated blood loss, and operative time were not significantly different. Overall morbidity was similar between groups.CONCLUSIONSOur results demonstrate a trend toward increased pathologic complete response rate and downstaging with increased RT-surgery interval. However, sphincter preservation is not increased. Until prospective analyses are conducted assessing the impact of prolonged RT-surgery interval on long-term outcome, the benefit of a prolonged interval between the completion of preoperative combined modality therapy and surgery remains unclear.

L576P KIT mutation in anal melanomas correlates with KIT protein expression and is sensitive to specific kinase inhibition

Activating mutations in either BRAF or NRAS are seen in a significant number of malignant melanomas, but their incidence appears to be dependent to ultraviolet light exposure. Thus, BRAF mutations have the highest incidence in non‐chronic sun damaged (CSD), and are uncommon in acral, mucosal and CSD melanomas. More recently, activating KIT mutations have been described in rare cases of metastatic melanoma, without further reference to their clinical phenotypes. This finding is intriguing since KIT expression is downregulated in most melanomas progressing to more aggressive lesions. In this study, we investigated a group of anal melanomas for the presence of BRAF, NRAS, KIT and PDGFRA mutations. A heterozygous KIT exon 11 L576P substitution was identified in 3 of 20 cases tested. The 3 KIT mutation‐carrying tumors were strongly immunopositive for KIT protein. No KIT mutations were identified in tumors with less than 4+ KIT immunostaining. NRAS mutation was identified in one tumor. No BRAF or PDGFRA mutations were identified in either KIT positive or negative anal melanomas. In vitro drug testing of stable transformant Ba/F3 KITL576P mutant cells showed sensitivity for dasatinib (previously known as BMS‐354825), a dual SRC/ABL kinase inhibitor, and imatinib. However, compared to an imatinib‐sensitive KIT mutant, dasatinib was potent at lower doses than imatinib in the KITL576P mutant. These results suggest that a subset of anal melanomas show activating KIT mutations, which are susceptible for therapy with specific kinase inhibitors.