Modern Trends in Surgical Site Infection Rates for Colorectal Surgery: A National Surgical Quality Improvement Project Study 2013-2020.

BACKGROUND: There are few studies investigating trends in global surgical site infection rates in colorectal surgery in the last decade. OBJECTIVE: This study seeks to describe changes in rates of different surgical site infections from 2013-2020, identify risk factors for SSI occurrence and evaluate the association of minimally invasive surgery and infection rates in colorectal resections. DESIGN: A retrospective analysis of the National Surgical Quality Improvement Program database 2013-2020 identifying patients undergoing open or laparoscopic colorectal resections by procedure codes was performed. Patient demographic information, comorbidities, procedures, and complications data were obtained. Univariable and multivariable logistic regression were performed. SETTING: This was a retrospective study. PATIENTS: A total of 279,730 patients received colorectal resection from 2013 - 2020. MAIN OUTCOME MEASURES: Primary outcome measure was rate of surgical site infection, divided into superficial, deep incisional and organ space infections. RESULTS: There was a significant decrease in rates of superficial infections (p < 0.01) and deep incisional infections (p < 0.01) from 5.9% in 2013 to 3.3% in 2020 and from 1.4% in 2013 to 0.6% in 2020, respectively, but a rise in organ space infections (p < 0.01) from 5.2% in 2013 to 7.1% in 2020. Use of minimally invasive techniques was associated with decreased odds of all surgical site infections compared to open techniques (p < 0.01) in multivariate analysis and adoption of minimally invasive techniques increased from 59% in 2013 to 66% in 2020. LIMITATIONS: Study is limited by retrospective nature and variables available for analysis. CONCLUSIONS: Superficial and deep infection rates have significantly decreased, likely secondary to improved adoption of minimally invasive techniques and infection prevention bundles. Organ space infection rates continue to increase. Additional research is warranted to clarify current recommendations for mechanical bowel prep and oral antibiotic use as well as to study novel interventions to decrease postoperative infection occurrence. See Video Abstract.

Romiplostim for Treatment of Children and Young Adults With Severe Aplastic Anemia and Myelodysplastic Syndrome.

Thrombopoietin receptor agonists (TPO-RAs) induce trilineage hematopoiesis under conditions with acquired hematopoietic failure. We evaluated safety, tolerability, and preliminary efficacy of a TPO-RA, romiplostim (Nplate), with or without standard-of-care immunosuppressive therapy (±IST) for children (ages <21 y) with newly diagnosed and relapsed/refractory severe aplastic anemia (SAA) and myelodysplastic syndrome (MDS). Data were collected from an observational study and a single arm interventional pilot study. The safety outcome was treatment-related adverse events (AEs). Efficacy was evaluated by complete hematopoietic response (CHR) at week 24. Romiplostim was commenced at 5 µg/kg/week, with dose escalation of 2.5 µg/kg/week (maximum, 20 µg/kg/dose) based on platelet response. Romiplostim was continued until CHR was observed. Ten subjects (SAA, 9 [IST, 4; without IST, 5]; MDS, 1) completed the study (median age: 9.2 y). Median romiplostim dose was 10 µg/kg/week (range: 5 to 17.5 µg/kg/week). The cumulative incidence of CHR was 70.4% (95% CI, 20.2%-92.6%). Among 21 AEs (Grade 1 to 3), 3 were attributed to romiplostim. At a median posttherapy follow-up of 10.9 months (range: 0.7 to 77.5), no clonal evolution, bone marrow fibrosis or mortality was reported. This proof-of-concept study provides data about short-term safety, tolerability, and preliminary efficacy of romiplostim (±IST) for treatment of pediatric SAA/MDS.

Pathologic Complete Response, Total Neoadjuvant Therapy and the Survival Paradox in Locally Advanced Rectal Cancer.

BACKGROUND: Pathologic complete response (pCR) after preoperative chemoradiation (nCRT) correlates with improved overall survival for patients with locally advanced rectal cancers (LARCs). Escalation protocols including total neoadjuvant therapy (TNT), which delivers multi-agent chemotherapy and chemoradiation before surgery, are associated with increased complete response rates. However, TNT is not associated with improved overall survival. The authors hypothesized that the route to pCR may be an important predictor of oncologic outcome. METHODS: Adults with LARC between 2006 and 2017 were identified in the National Cancer Database. The cohort was limited to those who received neoadjuvant radiation (45-70 Gy) and underwent proctectomy. RESULTS: Of 25,880 patients, 16 % received TNT and 84 % had nCRT followed by either multi-agent (27 %), single-agent (14 %), or no adjuvant chemotherapy (44 %). Overall, 18 % achieved pCR, with higher rates in the TNT cohort than in the nCRT (18 %) or multi-agent (14 %) chemotherapy cohorts. With control for covariates, the OS in the pCR cohort was similar for the patients that received single-agent therapy and those that received multi-agent adjuvant therapy, and superior to the TNT and no adjuvant therapy cohorts. Conversely, among the patients who did not achieve pCR, those who received single-agent chemotherapy had OS comparable with those who had multi-agent adjuvant therapy and TNT, which was better than no adjuvant therapy. CONCLUSION: Patients achieving pCR after TNT had worse OS than those who had CRT alone, suggesting that the neoadjuvant route by which pCR is achieved is prognostically relevant. Therefore, in the era of neoadjuvant therapy escalation, pCR does not necessarily portend a uniformly favorable prognosis.

Early experience with sequential intravesical gemcitabine and docetaxel for micropapillary variant non-muscle invasive bladder cancer.

BACKGROUND: Guidelines lack clear recommendations regarding conservative management of micropapillary (MP) variant non-muscle invasive bladder cancer (NMIBC). Bladder-sparing therapy using intravesical Bacillus Calmette-Guerin (BCG) has been reported although there are concerns regarding recurrence and progression with this approach. Due to the ongoing BCG shortage, we have utilized sequential intravesical gemcitabine and docetaxel (Gem/Doce) as primary therapy for NMIBC, including some cases with limited MP urothelial carcinoma (MPUC). To compare oncologic outcomes of patients with non-muscle invasive MPUC and conventional UC treated with Gem/Doce. METHODS: A secondary analysis of 138 patients with high-risk NMIBC treated with intravesical Gem/Doce from January 2011 to December 2021 was performed. Oncologic outcomes were compared in patients with or without MPUC using the Kaplan-Meier method. RESULTS: Median follow-up (f/u) for all patients was 23 months (IQR 13-34). There were 129 patients with pure UC and 9 with MPUC. In those with MPUC, all were high-grade (HG), 8/9 were stage T1, 7/9 had a focal MP component (extent < 10%), 3/9 had concomitant CIS, and 2/9 had lymphovascular invasion. All MPUC tumors were re-resected, and 4 had T0, 3 had T1 HG, 1 had Ta HG, 1 had carcinoma in situ (CIS); none had residual MP or LVI tumors before Gem/Doce treatment. The 24-month high-grade recurrence-free survival was 89% and 80% in patients with MPUC and pure UC, respectively. Survival outcomes did not significantly differ between patients with and without MPUC. Four patients with MPUC experienced recurrent NMIBC after Gem/Doce, and all were treated successfully with rescue sequential intravesical valrubicin and docetaxel (Val/Doce). Pathology of these four recurrent patients revealed more aggressive histologic features in the original tumor including: multifocal tumor (3/4), T1 HG disease (4/4), concomitant CIS (2/4), and moderate MP variant extent (30%) (1/4). No patient with MPUC underwent cystectomy, experienced progression, or died at last follow-up (median f/u of 43 months). CONCLUSIONS: Gem/Doce with Val/Doce rescue appears to have activity against carefully selected non-muscle invasive MPUC with favorable histology. Larger prospective trials are needed to validate these results.

Sequential endoluminal gemcitabine and docetaxel vs. Bacillus Calmette-Guérin for the treatment of upper tract carcinoma in situ.

INTRODUCTION: Nephroureterectomy is commonly performed for high-grade (HG) upper tract (UT) urothelial carcinoma (UC). However, some patients may benefit from a de-escalation of surgical management, particularly for noninvasive disease and carcinoma in situ (CIS). Bacillus Calmette-Guerin (BCG) is currently the only guideline-recommended endoluminal treatment option. Gemcitabine/Docetaxel (Gem/Doce) has shown promising efficacy as a treatment for noninvasive HG UTUC, though a comparison to BCG is lacking. We report the outcomes of patients treated with endoluminal Gem/Doce vs. BCG for UT-CIS. METHODS: A single-institutional retrospective review of patients treated with Gem/Doce vs. BCG for UT-CIS was performed. Treatment was instilled via nephrostomy or retrograde ureteral catheter. In both treatment groups, induction consisted of 6 weekly instillations. Maintenance was initiated if disease-free and consisted of 6 monthly instillations in the Gem/Doce group and a reduced dose (one-tenth) 3-week course at 3 months in the BCG group. Recurrence was defined as biopsy-proven disease or HG cytology. RESULTS: The final cohort included 53 patients with 65 upper tract units; 31 received BCG and 34 received Gem/Doce. Median follow-up was 88 and 29 months in the BCG and Gem/Doce groups, respectively. Presenting pathology included biopsy-proven CIS and HG cytology in 9.7% and 90% of the BCG group, and 8.8% and 91% of the Gem/Doce group, respectively. The 2-year estimates for recurrence-free and nephroureterectomy-free survival were 61% and 89% for the BCG group and 54% and 100% for the Gem/Doce group, respectively. Upon multivariable analysis, instillation via percutaneous nephrostomy tube was associated with an increased risk of recurrence (HR 3.89, 95% CI 1.59-9.53). The development of any symptom was not statistically different between treatment groups (P = 0.12). There were 2 treatment-related deaths that occurred, 1 within each treatment group. CONCLUSION: Endoluminal Gem/Doce and BCG have similar oncological outcomes and major adverse event rates in the treatment of UT-CIS. Further prospective evaluation is warranted.

A population-based analysis on the incidence of metachronous colon cancer after endoscopic resection of advanced adenomas with high-grade dysplasia: does location matter?

BACKGROUND: Advanced adenomas (AAs) with high-grade dysplasia (HGD) represent a risk factor for metachronous neoplasia, with guidelines recommending short-interval surveillance. Although the worse prognosis of proximal (vs distal) colon cancers (CCs) is established, there is paucity of evidence on the impact of laterality on the risk of subsequent neoplasia for these AAs. METHODS: Adults with HGD adenomas undergoing polypectomy were identified in the Surveillance, Epidemiology, and End Results database (2000-2019). Cumulative incidence of malignancy was estimated using the Kaplan-Meier method. Fine-Gray models assessed the effect of patient and disease characteristics on CC incidence. RESULTS: Of 3199 patients, 26% had proximal AAs. A total of 65 cases of metachronous adenocarcinoma were identified after polypectomy of 35 proximal and 30 distal adenomas with HGD. The 10-year cumulative incidence of CC was 2.3%; when stratified by location, it was 4.8% for proximal vs 1.4% for distal adenomas. Proximal location was significantly associated with increased incidence of metachronous cancer (adjusted hazard ratio, 3.32; 95% CI, 2.05-5.38). CONCLUSION: Proximal location of AAs with HGD was associated with >3-fold increased incidence of metachronous CC and shorter time to diagnosis. These data suggest laterality should be considered in the treatment and follow-up of these patients.

Transplant versus no transplant in myelodysplastic syndrome and acute myeloid leukemia with TP53 mutation; a referral center experience.

A remarkably high rate of post-transplant relapse in patients with TP53-mutated myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) calls to question the utility of allogeneic stem cell transplant (HSCT). We, therefore, performed a retrospective analysis to compare the outcomes between HSCT (N = 38) versus non-HSCT (N = 45) approaches. Patients in the HSCT cohort were younger (median age 63 vs. 72) while patients in the non-HSCT cohort more commonly had complex karyotype with chromosome 17 aberrancy and 5q deletion (p < .01). A total of 69 TP53 variants including 64 pathogenic variants, and 5 variants of undetermined significance were detected. Nine patients (4 in HSCT and 5 in non-HSCT) had multi-hit TP53 variants. After induction: 57.9% versus 56.6% in the HSCT versus non-HSCT cohort achieved morphologic complete remission. Median time to HSCT was 6 months and median follow-up was 15.1 months for HSCT and 5.7 months for non-HSCT. Median disease-free survival (DFS) and overall survival (OS) were 11.7 and 15.9 months for HSCT, and 4.1 and 5.7 months for non-HSCT cohorts, respectively. Non-relapse mortality at 12 months was 22% versus 44% for HSCT versus non-HSCT. In the HSCT cohort, the rate of grade II-IV acute and chronic graft-versus-host disease (GVHD) was 55% and 18%, respectively. None of the patients from the non-HSCT cohort were alive while four patients from the HSCT cohort were alive, in remission, and without GVHD (GRFS) at the time of abstraction. Better treatment strategies for patients with TP53-mutated MDS/AML remain an area of unmet clinical need.

Impact of bladder cancer family history on the prognosis of patients with non-muscle invasive bladder cancer treated with Bacillus Calmette-Guerin (BCG).

BACKGROUND: To evaluate the impact of having first-degree relatives (FDR) with bladder cancer (BC) among non-muscle invasive bladder cancer (NMIBC) patients treated with Bacillus Calmette - Guérin (BCG) on their oncological outcomes. METHODS: The National Phase II BCG/Interferon (IFN) trial database from 125 sites in the U.S.A. (1999-2001) and multi-institutional databases from France (FR) and Lebanon (LB) (2000-2021) were queried for NMIBC patients treated with BCG. Cox regression models were used to evaluate the effect of BC family history on tumor recurrence and progression in their relatives. RESULTS: There were 867 patients in the U.S.A. cohort and 1232 patients in the FR/LB cohort. Almost 8% of patients in both cohorts had FDR with BC. Patients in the FR/LB cohort were more likely to have carcinoma in situ tumors (CIS) (41% vs. 24%, p < 0.01). Having FDR with BC was not significantly associated with tumor recurrence or progression in the U.S.A. cohort. Conversely, on multivariable analysis FDR history was significantly associated with a 2.10 times increased risk of recurrence (p < 0.01) and a 3.01 times increased risk of progression (p < 0.01) in the FR/LB cohort. CONCLUSION: A family history of BC could have an important impact on the response to BCG.

Longitudinal Outcomes of Malignant Ureteral Obstruction Secondary to Ovarian Cancer: Predictors of Resolution and the Role of Surgical Management.

OBJECTIVE: To review the management of ovarian cancer (OCa) associated hydronephrosis (HN). Specifically, we aim to identify optimal management of HN in the acute setting, predictors of HN resolution, and the role of surgery (tumor debulking/(+/-)ureterolysis/hysterectomy). MATERIALS/METHODS: The study cohort included OCa patients managed at our institution from 2004-2019 that developed OCa-associated HN. Initial HN management was recorded as none, retrograde ureteral stent (RUS) or percutaneous nephrostomy tube (PCN). Primary outcomes included (1) HN management failure, (2) HN management complications, and (3) HN resolution. Patient, cancer, and treatment predictors of outcomes were assessed using logistic regression and fine-Gray competing risk models. RESULTS: Of 2580 OCa patients, 190 (7.4%) developed HN. HN was treated in 121; 90 (74.4%) with RUS, 31 (25.6%) with PCN. Complication rates were similar between PCN and RUS (83% vs 85.1%; P = .79; all Clavian Grade I/II). Initial HN treatment failure occurred in 28 patients, predicted by renal atrophy (hazard ratios (HR) 3.27, P <.01). HN resolution occurred in only 52 (27%) patients and was predicted by lower International Federation of Gynecology and Obstetrics (FIGO) stage (FIGO III/IV HR 0.42, P <.01) and surgical tumor debulking/ureterolysis (HR 2.83, P = .02). CONCLUSION: Resolution of HN associated with malignant obstruction from OCa is rare and is most closely associated with tumor debulking and International Federation of Gynecology and Obstetrics (FIGO) stage. Initial endoscopic treatment modality was not significantly associated with complications or resolution, though RUS failures were slightly more common. Ureteral reconstruction at time of debulking/ureterolysis is potentially underutilized.

Sequential endoluminal gemcitabine and docetaxel for the treatment of clinically non-invasive high-grade upper tract urothelial carcinoma.

PURPOSE: There is an unmet need for effective renal sparing treatments for upper tract urothelial carcinoma (UTUC). Gemcitabine/Docetaxel (Gem/Doce) has shown favorable efficacy in nonmuscle invasive bladder cancer. We report the outcomes of patients treated with endoluminal Gem/Doce for noninvasive high-grade UTUC. METHODS: A retrospective review of patients treated with Gem/Doce for clinically noninvasive high-grade UTUC with no radiographic or endoscopically visible disease, either at diagnosis or following ablation, was performed. Treatment was instilled via nephrostomy or retrograde ureteral catheter. Induction instillations were performed weekly for 6 weeks, followed by 6 monthly instillations if disease-free. Recurrence was defined as biopsy-proven disease or high-grade (HG) cytology. Progression was defined by development of muscle invasion, metastases, or death due to cancer. Survival was assessed with the Kaplan-Meier method. RESULTS: The final cohort included 31 patients with 41 upper tract units, 51% of which would have been dialysis dependent with nephroureterectomy. Median (IQR) age was 74 years (68-81). Median follow-up was 29 months (IQR 20-58). Prior to treatment, 37 (90%) units presented with a localizing HG cytology (presumed occult CIS), and 4 (9.8%) with HG biopsy-proven disease. Sixteen (52%) patients reported any side effects; 5 were Grade 3 and 1 was Grade 5. Recurrence-free survival was 76%, 54%, and 40% at 1, 2, and 3 years, respectively. Five patients died from urothelial carcinoma. The 3-year progression-free and overall survival were 75% and 75%, respectively. CONCLUSIONS: Gem/Doce demonstrates promising safety and efficacy as a renal-sparing treatment option for high-grade UTUC in appropriately selected patients.

Conditional Overall Survival After Diagnosis of Non-Metastatic Colon Cancer: Impact of Laterality, MSI, and KRAS Status.

BACKGROUND: The prognostic relevance of laterality, microsatellite instability (MSI), and KRAS status in colon cancer has been established. However, their effect on conditional overall survival (COS) remains unknown. METHODS: COS is the probability of surviving additional years after a time from diagnosis. The National Cancer Database (2010-2017) was queried for adults with non-metastatic colon cancer and known mutation status undergoing curative resection. COS was investigated at 2 years. RESULTS: Of 4838 patients, 3716 survived at least 2 years: 15% had stage I, 38% stage II, and 46% stage III disease. Fifty-nine percent had a right-sided tumor, 16% were MSI-high, and 37% were mutated KRAS (mKRAS). The proportion of patients alive at 2 years was higher for stage I compared with stage II and III (65 vs. 61 vs. 54%). The 5-year overall survival for stage I-III was 80, 76, and 67% for the initial cohort, and 90, 88, and 86% for those alive at 2 years. After adjustment, higher pathologic T and N stage, tumor deposits, and no chemotherapy were associated with worse COS (p < 0.01). While laterality and MSI status were not associated with COS, mKRAS was independently associated with decreased COS (HR 1.35, 95% CI 1.12-1.62). CONCLUSION: Patients with mKRAS had worse COS, suggesting that these mutations confer an aggressive biologic behavior, with patients remaining at higher risk of death 2 years after diagnosis. Routine evaluation of KRAS status should be considered in patients with non-metastatic disease for prognostication and to identify those who might benefit from modified surveillance protocols.

Venetoclax-based therapy in treatment-naïve and relapsed/refractory acute myeloid leukemia.

Combining venetoclax with the hypomethylating agents azacitidine or decitabine has shown high complete response rates (60-70 %) in newly diagnosed (ND) acute myeloid leukemia (AML). However, studies addressing the efficacy of this approach in relapsed/refractory (R/R) AML remain limited. We conducted a retrospective analysis on patients treated with venetoclax-based therapy at a single institution. Objective response rates (ORR) and overall survival (OS) were assessed using logistic regression and Cox regression models, respectively. The total study population exhibited an ORR of 64 % with a complete remission at 34 %, complete remission with incomplete count recovery at 19%, and morphologic leukemia free state at 11 %. Patients with ND AML had a better ORR (71 %) compared to R/R AML (55 %), but the difference was not statistically significant. Median OS for the overall population was 14.4 months (range: 2-26 months). In the ND group, patients had a longer 6-month OS (82 % vs. 55 % in R/R AML), while both cohorts showed similar 12- and 24-month OS. Factors such as the hypomethylating agent chosen, adverse cytogenetics, TP53 mutations, prior hypomethylating agent use, and stem cell transplant status did not significantly affect ORR or OS. These findings support the effectiveness of venetoclax-based treatments in ND and R/R AML.

Responding to distress in cancer care: Increasing access to psycho oncology services through integrated collaborative care.

OBJECTIVE: Despite increased attention to the utility of collaborative care models for promoting whole-person care in cancer populations, there is a paucity of empirical research testing the impact of these care models on effectively identifying and serving highly distressed cancer patients. This study sought to experimentally test the effectiveness of a year-long collaborative care program on referral rates to psycho-oncology services for patients with moderate to high distress. METHODS: Data for this study consisted of 11,467 adult patients with cancer who were screened for psychosocial distress 6-months prior to, and following, the integrated collaborative care intervention. Psychosocial referral rates pre-, peri- and post- intervention were analyzed. RESULTS: Findings indicated high distress patients were at 3.76 (95% CI [2.40, 5.87]), 5.03 (95% CI [3.25, 7.76]), and 7.62 (95% CI [5.34, 10.87]) times increased odds of being referred during the pre-intervention, peri-intervention, and post-intervention, respectively, when compared to low distress patients, and these differences across time were significantly different (p = 0.04). CONCLUSION: Findings from this study suggest that the successful initiation of a collaborative care model within a comprehensive cancer center contributed to significantly greater referral rates of cancer patients with moderate to high distress to psycho-oncology services. This study contributes to the growing consensus that collaborative care models can positively impact the care of complex medical patients.

Sequential intravesical gemcitabine/docetaxel provides a durable remission in recurrent high-risk NMIBC following BCG therapy.

PURPOSE: Bacillus Calmette-Guerin (BCG) is the standard of care for high-risk nonmuscle invasive bladder cancer (NMIBC), but half of patients develop disease recurrence. Intravesical regimens for BCG unresponsive NMIBC are limited. We report the safety, efficacy, and differential response of sequential gemcitabine/docetaxel (gem/doce) depending on BCG failure classification. METHODS: Multi-institutional retrospective analysis of patients treated with induction intravesical gem/doce (≥5/6 instillations) for recurrent high-risk NMIBC after BCG therapy from May 2018 to December 2021. Maintenance therapy was provided to those without high-grade (HG) recurrence on surveillance cystoscopy. Kaplan-Meier curves and Cox regression analyses were utilized to assess survival and risk factors for disease recurrence. RESULTS: Our cohort included 102 patients with BCG-unresponsive NMIBC. Median age was 72 years and median follow-up was 18 months. Six-, 12-, and 24-month high-grade recurrence-free survival was 78%, 65%, and 49%, respectively. Twenty patients underwent radical cystectomy (median 15.5 months from induction). Six patients progressed to muscle invasive disease. Fifty-seven percent of patients experienced mild/moderate adverse effects (AE), but only 6.9% experienced a delay in treatment schedule. Most common AE were urinary frequency/urgency (41%) and dysuria (21%). Patients with BCG refractory disease were more likely to develop HG recurrence when compared to patients with BCG relapsing disease (HR 2.14; 95% CI 1.02-4.49). CONCLUSIONS: In patients with recurrence after BCG therapy, sequential intravesical gem/doce is an effective and well-tolerated alternative to early cystectomy. Patients with BCG relapsing disease are more likely to respond to additional intravesical gem/doce. Further investigation with a prospective trial is imperative.

Use of subgroup-specific hematopoietic stem cell collection efficiencies to improve truncation calculations for large-volume leukapheresis procedures.

PURPOSE: A critical component of optimizing peripheral blood (PB) hematopoietic stem cell (HSC) collections is accurately determining the processed blood volume required to collect the targeted number of HSCs. Fundamental to most truncation equations employed to determine this volume is the procedure's estimated collection efficiency (CE), which is typically applied uniformly across all HSC collections. Few studies have explored the utility of using different CEs in subpopulations of donors that have substantially different CEs than the institutional average. METHODS: Initial procedures from 343 autologous and 179 allogeneic HSC collections performed from 2018 to 2021 were retrospectively analyzed. Predictive equations were developed to determine theoretical truncation rates in various donor subgroups. RESULTS: Quantitative variables (pre-procedure cell counts) and qualitative variables (relatedness to recipient, gender, method of venous access, and mobilization strategy) were found to significantly impact CE. However, much of the variability in CE between donors could not be explained by the variables assessed. Analyses of procedures with high pre-collection PB cell counts identified lower CE values for these donors' truncation equations which still allow truncation but minimize risk of collecting less CD34+ cells than requested. CONCLUSIONS: Individualized CE does not substantially improve truncation volume calculations over use of a fixed CE and adds complexity to these calculations. The optimal fixed CE varies between autologous and allogeneic donors, and donors with high pre-collection PB cell counts in either of these groups. This model will be clinically validated and continuously refined through analysis of future HSC collections.