Methods
This was a retrospective record review of colorectal malignancies treated with curative intent at the Veterans Affairs Ann Arbor Healthcare System (VAAAHS) in Michigan between January 1, 2015, and December 31, 2019. We examined nutritional status, degree of longitudinal weight loss, and subsequent clinical outcomes, including delayed postoperative recovery and delays in chemotherapy in 115 patients with CC and 33 patients with rectal cancer (RC) undergoing curative surgical resection at VAAAHS. To avoid additional confounding effects of advanced cancer, only early-stage, curable disease was included. This study was approved by the VAAAHS Institutional Review Board.
Patients with postoperative follow-up outside of VAAAHS were excluded. Patients were excluded if their surgery had noncurative intent or if they had distant metastatic disease. Data on patient weights, laboratory results, nutrition consultations, postoperative complications, delayed recovery, readmissions, and chemotherapy tolerance were abstracted by patient chart review in the VHA Computerized Patient Record System and Joint Legacy Viewer by 2 researchers.
Delayed recovery was defined as any abnormal clinical development described in inpatient progress notes, outpatient follow-up notes within 60 days, or in hospital discharge summaries. Excluded were psychiatric events without additional medical complications, postoperative bleeding not requiring an invasive intervention, urinary retention, postoperative glycemic control difficulties, cardiac events that happened before postoperative hospital discharge and not requiring readmission, and postoperative alcohol withdrawal. Complications were defined similarly to delayed recovery but excluded isolated prolonged postoperative ileus. LOS was defined in days as time from admission to discharge.
Adjuvant management course was derived from reviewing documentation from medical oncology consultations and progress notes. In patients for whom adjuvant chemotherapy was indicated and prescribed, chemotherapy was considered complete if chemotherapy was started and completed as indicated. Adjuvant chemotherapy was considered incomplete if the patient declined chemotherapy, if chemotherapy was not started when indicated, or if chemotherapy was not completed as indicated. Neoadjuvant therapy data were abstracted from medical and radiation oncology notes.
Recorded data were collected on both weight and BMI. Weights were extracted as follows: Weight 1 year before time of diagnosis, ± 4 months; weight 6 months before diagnosis ± 3 months; weight at time of diagnosis ± 2 weeks; weight at time of surgery ± 2 weeks; weight 30 days postsurgery ± 2 weeks; weight 60 days postsurgery ± 2 weeks; weight 1 year postsurgery ± 4 months. Mean percent change in weight was calculated from recorded weights between each allocated time point. A weight loss of ≥ 3% was found to be clinically relevant and was chosen as the minimal cutoff value when analyzing outcomes associated with weight trends.
Nutrition consultations were abstracted as follows: Preoperative nutrition consultations were defined as occurring between time of cancer diagnosis and surgery in either the inpatient or outpatient setting; inpatient postoperative nutrition consultations occurred during admission for surgery; readmission nutrition consultations occurred on readmission in inpatient setting, if applicable; outpatient postoperative nutrition consultations were defined as occurring up to 2 months postdischarge in the outpatient setting.
Albumin values were extracted as follows: Preoperative albumin levels were defined as up to 4 months prior to diagnosis, and postoperative albumin levels were defined as 2 to 6 months after surgery.