Introduction 1 2 3 4 5 7 8 9 To determine if patients treated for gastric cancer at high-volume and specialized centers in the US had better postoperative outcomes, we analyzed the preoperative evaluation and surgical treatment of gastric adenocarcinoma at three categories of hospitals, defined by the Commission on Cancer (CoC), namely, the Community Hospital Cancer Program (CHCP), Community Hospital Comprehensive Cancer Program (COMP), and Teaching Hospital Cancer Program (THCP). Data collected for the 2001 Gastric Cancer Patient Care Evaluation (PCE) by the NCDB were utilized. Material and Methods NCDB, Data Source, Case Selection, and Data Handling The NCDB is a project of the American College of Surgeons (ACS) CoC. The NCDB was established in 1989 to serve as a comprehensive clinical surveillance resource for all forms of cancer diagnosed in the US and its operations have been supported in part by the American Cancer Society. In 2001, the database captured 73% of all newly diagnosed cancer cases in the US. 10 Registry Operations and Data Standards, volume II 11 Patient Population The 2001 Gastric PCE included data submitted from 711 CoC-approved institutions in the US. Participating institutions submitted data for consecutive hospital admissions and clinic visits between January 1, 2001 and December 31, 2001. Patients eligible for participation had a “microscopically confirmed neoplasm of the stomach that was either diagnosed or initially treated at the reporting facility.” Of 7,084 total patients, 6,099 (86%) were diagnosed with gastric adenocarcinoma. For this study, 52 patients were excluded because they were treated at nine institutions without a specialized hospital type, leaving 6,047 patients at 691 cancer program types for evaluation. This group comprises the study population. Cancer Program Categories Cancer programs were characterized as CHCP, COMP, or THCP. Community Hospital Cancer Programs diagnose and/or treat 100–650 cancer patients every year and will commonly refer patients to other institutions for diagnostic evaluation or treatment. A CHCP has neither a medical school affiliation nor residency programs but does posses a medical oncology unit or functional equivalent and infrequently participates in cancer research. Community Hospital Comprehensive Cancer Programs diagnose and/or treat more than 650 cancer cases per year, but are not associated with a medical school. A COMP may make outside patient referrals, has a medical oncology unit, and participates in cancer research. Teaching Hospital Cancer Programs are defined as facilities associated with a medical school that participates in the training of residents in at least four fields, two of which are medicine and surgery. A THCP offers a full range of diagnostic and therapeutic services on site and has an in-patient medical oncology unit. A THCP hospital also participates in cancer-related clinical research and has board-certified medical oncologists. Statistical Analysis χ 2 p 12 p A forward stepwise binary logistic regression model was used to evaluate the impact of age, stage, and comorbid burden on determination of type of treatment, i.e., the odds of “surgery, with or without other treatment” compared to the odds of nonsurgical treatment (radiation and/or chemotherapy). The Wald statistic was used to test significance. Exponentiated estimates of the beta coefficients were interpreted as the estimates for the effect (odds ratio) of a particular variable, controlling for the other variables in the equation. A receiver operating characteristic (ROC) curve was created to examine the prediction results. The true-positive probability was calculated to define the sensitivity of the classification rule and the true-negative probability was calculated to determine the specificity to summarize how well the model performed. Confidentiality Data reported to the NCDB are retrospective in nature. No patient or physician identifiers were collected as part of the study. Case identification information (facility identification number and local registry accession number) was collected for administrative purposes only. Analyses were reported only at the aggregate level to assist hospital cancer programs with quality assurance, rather than used to make decisions about individuals and their care. The ACS has executed a business associate agreement that includes a data-use agreement, with each of its CoC-approved hospitals. Results reported in this study were in compliance with the privacy requirements of the Health Insurance Portability and Accountability Act of 1996 as reported in the Standards for Privacy of Individually Identifiable Health Information; Final Rule (45 CFR Parts 160 and 164). Results Treatment Volumes n n n 1 Table 1 Number and Percent of Cancer Programs, Number and Percent of Patients by Cancer Program, Mean Number and Range of All Cases by Cancer Program Type, Number and Percent of Surgically Treated Cases, and Mean Number of Surgical Cases and Range by Cancer Program Type   Community Cancer Centers Comprehensive Community Cancer Centers Teaching/Research Hospitals Total Number (%) of cancer programs 258 (37.3) 267 (38.6) 166 (24.0) 691 Number (%) of patients in study 1,329 (22.0) 2,468 (40.8) 2,250 (37.2) 6,047 Mean number and range of all cases 5.2 (1–39) 9.2 (1–49) 13.6 (1–55)  Number (%) of surgical cases 673 (20.5) 1,369 (41.8) 1,235 (37.7) 3,277 Mean number and range of surgical cases 2.9 (1–16) 5.3 (1–37) 7.6 (1–40)  Patient Demographics p p 2 Table 2 Patient Characteristics by Type Cancer Program   Community Cancer Center Comprehensive Cancer Center Teaching/Research Total n n n n Gender Male 805 (60.6) 1,502 (60.9) 1,444 (64.2) 3,751 (62.0) Female 524 (39.4) 966 (39.1) 806 (35.8) 2,296 (38.0) Total 1,329 2,468 2,250 6,047 Age <50 106 (8.0) 207 (8.4) 264 (11.7) 577 (9.5) 50–69 402 (30.2) 865 (35.0) 836 (37.2) 2,103 (34.8) 70 and older 821 (61.8) 1,396 (56.6) 1,150 (51.1) 3,367 (55.7) Total 1,329 2,468 2,250 6,047 Race/Ethnicity Caucasian 966 (72.7) 1,723 (69.8) 1,387 (61.6) 4,076 (67.4) African American 143 (10.8) 278 (11.3) 406 (18.0) 827 (13.7) Hispanic 120 (9.0) 206 (8.3) 207 (9.2) 533 (8.8) Asian 78 (5.9) 218 (8.8) 176 (7.8) 472 (7.8) Other 22 (1.7) 43 (1.7) 74 (3.3) 139 (2.3) Total 1,329 2,468 2,250 6,047 AJCC stage O 2 (0.2) 8 (0.3) 2 (0.1) 12 (0.2) I 13 (1.0) 28 (1.1) 26 (1.2) 67 (1.1) IA 105 (7.9) 210 (8.5) 182 (8.1) 497 (8.2) IB 118 (8.9) 218 (8.8) 178 (7.9) 514 (8.5) II 160 (12.0) 286 (11.6) 242 (10.8) 688 (11.4) III 6 (0.3) 12 (0.5) 12 (0.5) 30 (0.5) IIIA 156 (11.7) 347 (14.1) 337 (15.0) 840 (13.9) IIIB 47 (3.5) 96 (3.9) 97 (4.3) 240 (4.0) IV 427 (32.1) 856 (34.7) 835 (37.1) 2,118 (35.0) Unknown 295 (22.2) 407 (16.5) 339 (15.1) 1,041 (17.2) Total 1,329 2,468 2,250 6,047 p p p n n n n 1 Figure 1 A B C  Diagnostic Testing n p p n p 18 d p Intraoperative Assessment p p Surgical Treatment n p p 0 1 0 1 p p p 2 3 Figure 2 p  Table 3 Lymph Nodes Sampled During Surgical Resection Resected Community Cancer Center Comprehensive Cancer Center Teaching/Research n n n a Yes 367 (71.1) 775 (68.9) 715 (70.4) No 149 (28.9) 350 (31.1) 301 (29.6) b Yes 21 (4.2) 68 (6.5) 70 (7.5) No 478 (95.8) 979 (93.5) 867 (92.5) c Yes 40 (7.9) 100 (9.5) 96 (10.1) No 465 (92.1) 952 (90.5) 854 (89.9) d Yes 14 (2.8) 49 (4.7) 52 (5.5) No 481 (97.2) 988 (95.3) 887 (94.5) e Yes 94 (18.8) 170 (16.8) 189 (20.2) No 405 (81.2) 840 (83.2) 745 (79.8) Comparison of column proportions did not include the unknown values in calculations. a n b n c n d n e n Morbidity and Mortality 4 4 p p p p p p p p p Table 4 Postoperative Mortality and Complications   Community Cancer Center Comprehensive Cancer Center Teaching/Research n n n a Yes 55 (9.9) 93 (7.9) 59 (5.5) No 501 (90.1) 1,080 (92.1) 1,020 (94.5) b    Yes 20 (4.2) 40 (3.9) 47 (5.1) No 451 (95.8) 993 (96.1) 881 (94.9) c Yes 35 (7.4) 54 (5.2) 61 (6.6) No 440 (92.6) 981 (94.8) 868 (93.4) d    Yes 34 (7.1) 62 (6.0) 43 (4.7) No 443 (92.9) 973 (94.0) 881 (95.3) e Yes 32 (6.7) 68 (6.5) 64 (6.6) No 447 (93.3) 979 (93.5) 884 (93.2) Comparison of column proportions did not include the unknown values in calculations. a n b n c n d n e n Neoadjuvant and Adjuvant Therapy p 5 Table 5 Radiation and Chemotherapy/Surgery Sequence   Community Cancer Center Comprehensive Cancer Center Teaching/Research # (%) # (%) # (%) a Neoadjuvant 23 (12.1) 53 (13.0) 68 (19.1) Adjuvant 167 (87.9) 356 (87.0) 288 (80.9) b Neoadjuvant 36 (14.6) 71 (15.0) 87 (20.3) Adjuvant 210 (85.4) 401 (85) 342 (79.7) Comparison of column proportions did not include the unknown values in calculations. a n b n Discussion 6 13 6 1 14 15 16 15 16 17 18 19 20 21 22 23 9 24 Interpretation of the Results Our study had similar results to the aforementioned American, Japanese, and European studies. In this study, there was a marked improvement (>50%) in operative mortality at higher volume centers (≥14 cases/year) when compared to lowest volume institutions (≤5 cases/year). The average 30-day postoperative mortality at the low-volume community centers was almost 10%. The annual volume of gastric surgeries performed seems to be inversely related to 30-day postoperative mortality. On average 2.9, 5.5, and 7.6 gastric surgeries were reported from CHCPs, COMPs, and THCPs, respectively. Corresponding 30-day mortality was 9.9, 7.9, and 5.5%, respectively. There were no significant differences seen in postoperative morbidities such as wound infection and hemorrhage by hospital category. The logistical model revealed three predictors of perioperative mortality: stage IV disease, advanced age, and institution type. Patients that had surgery at a CHCP were twice as likely to die postoperatively compared to patients treated surgically at THCPs. Among those that died, there were no significant differences of stage or age at the different institutions. Because the absolute differences in surgical case number among the hospital types were not vastly different, this observed difference in outcomes may be a reflection of the infrastructure of the institution rather than individualized surgeon skill. Centers affiliated with a medical school might have more experience with caring for the critically ill in the form of larger and better equipped intensive care units, resident and fellow coverage, newer technology, and more subspecialized physicians to help manage patient care. Unfortunately, we could not analyze the infrastructure for each hospital type nor look at surgeon-specific experience in this study as this was not a part of the study. Clinical staging is affected by the sensitivity and specificity of the diagnostic studies performed during the preoperative evaluation. An assessment of staging at the different institutions revealed some major differences. Teaching hospitals were more likely to detect malignancy on a CT of the abdomen and pelvis than the other two hospital types. This might be a reflection on the quality of CT scans obtained and the experience of the radiologists. Preoperative utilization of endoscopic ultrasound was higher at teaching hospitals, a predictable finding given the recent adaptation of this technology and the expertise required to interpret these images. 25 26 To improve and obtain accurate surgical staging of gastric cancer patients, current practice will have to improve and will be dependent upon both the excision of nodes by the surgeon and their retrieval from the specimen by the pathologist. Given so few patients had 15 or more nodes removed at the time of surgery, regardless of hospital type, this practice could be improved by surgeons and pathologists working together to achieve the goal of identifying at least 15 nodes followed by the proper documentation of the microscopic evaluation of these nodes in the pathology report. If intraoperative pathologic evaluation of the surgical specimen is possible and the lymph node sampling is inadequate, the surgeon should excise additional lymph nodes. A strength of this study is the large number of patients and hospitals included in the study. This broad sampling of hospitals leads to a close approximation of the current practice of gastric cancer treatment in the US. The main shortcoming is that many of the critical data categories had at least 20% “unknown” responses, and may have biased the reported results of this study. In addition, analysis of hospital infrastructure or surgeon volume was limited by lack data availability in the database. Another limitation is that the 5-year survival information has not yet been documented; these data will provide long-term outcome by type of treatment center. Conclusion Data from the Gastric PCE project suggests that there is significant room for improvement in the surgical management of gastric cancer in the US. Most hospitals, regardless of category, do not document the evaluation at least 15 lymph nodes necessary to meet AJCC standards. With a little over one third of all patients having more than 15 lymph nodes examined, pathologic staging is less accurate and results of surgical and adjuvant therapy are likely to be worse. Significantly more patients had appropriate staging with the recommended number of nodes included in the lymphadenectomy at teaching centers than at nonacademic centers. Thirty-day mortality rates after gastric cancer resection were significantly lower at teaching centers, further establishing the recommendation that complex oncologic operations should be performed at high-volume centers to obtain better patient outcomes, corroborating the results of several previous studies. Long-term survival data will provide more information on effectiveness of treatment at each of the different institution types.