The aim of a surveillance program is to detect cancer recurrence at an early stage so that a curative intervention can be implemented. The purpose of this study was to utilize two U.S.-based, multi-institutional databases to: 1) evaluate the optimal surveillance modality after curative resection of primary soft-tissue sarcoma(STS) 2) evaluate the optimal surveillance frequency after cytoreductive surgery(CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC) for stage IV appendiceal or colorectal cancer 3) compare the costs to the US-Healthcare system between surveillance modalities and frequencies.
For aim 1, patients in the US-Sarcoma Collaborative(2000-2016) who underwent resection of primary, high-grade STS were included. When considering age, tumor size, location, margin status, and receipt of radiation, lung metastasis was independently associated with worse overall survival(OS) (HR:4.26; p<0.01) while imaging modality was not (HR:1.01; p=0.97). Patients surveyed with CXR did not have a worse 5-year OS compared to CT(71%vs60%, p<0.01). When analyzing patients in whom no lung metastasis was detected, both cohorts had a similar 5-year OS(73%vs74%, p=0.42), suggesting CXR was not missing clinically relevant lung nodules.
For aim 2, the US-HIPEC Collaborative(2000-2017) was reviewed for patients who underwent CRS+/-HIPEC for appendiceal or colorectal cancer. Radiologic surveillance frequency was divided into low-frequency surveillance(LFS) at every 6-12 months or high-frequency surveillance(HFS) at every 2-4 months. Despite less surveillance, patients surveyed at low-frequency had no decrease in median OS(non-invasive appendiceal: 106vs65 months, p<0.01; invasive appendiceal: 120vs73 months, p=0.02; colorectal cancer: 35vs30 months, p=0.8). On multivariable analysis, accounting for burden of disease, LFS was still not associated with decreased OS for any histologic type(non-invasive appendiceal: HR:0.28, p=0.1; invasive appendiceal: HR:0.73, p=0.42; colorectal cancer: HR:1.14, p=0.59).
When adhering to a guideline-specified protocol for 4,406 projected cases, surveillance with CXR results in savings of $5-8M/year. Similarly, when estimating annual incident cases of CRS/HIPEC at 375 for non-invasive appendiceal, 375 invasive appendiceal and 4410 colorectal, LFS compared to HFS saves $13-19M/year.
Utilizing CXR for surveillance of high-grade STS or LFS after CRS+/-HIPEC for appendiceal/colorectal cancer is not associated with decreased OS. Considering substantial savings to the US-healthcare system, surveillance protocols for patient cohorts could be modified accordingly to optimize resource utilization.
Table of Contents
AIM 1. 4
AIM 2. 9
AIM 3. 15
STRENGHTS AND LIMITATIONS: AIM 1. 18
STRENGTHS AND LIMITATIONS: AIM 2. 18
STRENGTHS AND LIMITATIONS: AIM 3. 19
Table 1. 25
Table 1.2. 27
Table 2.1. 28
Table 2.2. 31
Table 3.1. 33
Table 3.2. 34
Table 3.4. 35
Table 4.4. 36
Figure 1.1. 37
Figure 2.1 38
About this Master's Thesis
|Committee Chair / Thesis Advisor|
|Optimal Post-Treatment Surveillance for Sarcoma, Colorectal and Appendiceal Neoplasms ()||2020-04-29 13:42:04 -0400||
|Signature Page ()||2020-04-28 20:35:44 -0400||
|Distribution Agreement ()||2020-04-28 20:35:48 -0400||