Prognostic Factors For Time To Progression Research Articles

Prognostic Significance of the Stage at Which an MRD-Negative Status Is Achieved for Patients With Multiple Myeloma Who Received ASCT.

ObjectiveTo explore the prognostic significance of the stage at which a minimal residual disease (MRD)-negative status is achieved for patients with newly diagnosed multiple myeloma (NDMM) who received autologous hematopoietic stem cell transplantation (ASCT).Cases and MethodsA retrospective analysis of 186 NDMM patients who received “induction therapy-ASCT-maintenance therapy” in our center and achieved an MRD-negative status was performed. Patients were divided into three groups, A (induction therapy), B (3 months after ASCT), and C (maintenance therapy), according to the stage at which an MRD-negative status was achieved.ResultsThe median time to progression (TTP) of 186 patients was not reached; the median overall survival (OS) was 113.8 months. The median TTP of the patients in three groups was not reached (P=0.013), and the median OS of the patients in three groups was not reached, not reached, and 71.2 months, respectively (P=0.026). Among patients with standard-risk cytogenetics, the median TTP of those in all three groups was not reached (P=0.121), and the median OS of the patients in three groups was not reached, not reached, and 99.6 months, respectively (P=0.091). Among patients with high-risk cytogenetics, the median TTP of those in three groups was not reached, 53.9 months, and 35.8 months (P=0.060), and the median OS was not reached, 71.2 months, and 60.2 months, respectively (P=0.625). Among patients with R-ISS stage I-II, the median TTP of those in three groups was not reached (P=0.174), and the median OS of the patients in three groups was not reached, not reached, and 99.6 months, respectively (P=0.186). Among the 29 patients with R-ISS stage III, the median TTP of those in the 3 groups were unreached, unreached, and 35.1 months (P<0.001), and the median OS was unreached, unreached, and 48.5 months, respectively (P=0.020). In all enrolled patients, the stage of reaching MRD-negative was an independent prognostic factor for TTP, rather than a prognostic factor for OS. The stage of reaching MRD-negative in patients with R-ISS III was an independent prognostic factor for OS.ConclusionFor the same patients who are MRD-negative, the prognoses of those who achieve an MRD-negative status at different groups are different. The stage at which an MRD-negative status is achieved can predict the prognosis of patients with R-ISS stage III.

Progression prediction model for solid tumors with clinical and immunological parameters.

2539 Background: The immune system has well-known relation to tumor progression. Numerous immune-related parameters exist, but only a minor part could be used as biomarkers, especially dynamic ones. We trained a progression prediction model based on clinical features and peripheral immune system assessments. Methods: Patients with immunogenic (melanoma, 295, kidney cancer, 81), non-immunogenic (soft tissue sarcoma, 47, colorectal cancer, 26) and multiple primary tumors (29) with immunologic assessments before treatment (23.5%), on therapy (58.3), and in follow-up after the treatment (18.2%) were randomly divided in 7:3 ratio to the training and test groups. Counts of lymphocytes, T-, B, NK cells, cytotoxic lymphocytes, T-helpers were used as immunologic parameters. Age, sex, disease, stage, therapy, mutational status, last response on treatment, disease and therapy duration, previous treatments were used as clinical ones. The model was trained to predict disease progression in the next three months using “Catboost” gradient boosting. We used ROC AUC to test model performance and Yoden’s index for optimal cutoff calculation. We also studied the influence of model prediction on overall survival (OS) and time to progression (TTP) on the test dataset using the Kaplan-Meyer method and Cox regression. Results: We used 1682 assessments of immune parameters (immune status, IS) done in 354 patients (average 5 per patient) to train the model and 616 IS in 124 patients for validation. All IS of one patient were in the same group. The ROC AUC value of the model was 0.801. The model prediction of progression increased the probability of progressive disease from 37.5 to 62% and decreased the response rate from 37,5% to 8.4% (p = 0.016). The model prediction did not add information over known prognostic factors for OS in the multifactorial model but was an independent prognostic factor for TTP (HR 2.204, p = 0.011). False-positive results separate the group of patients with poor prognosis (OS 16 months, TTP 6 months) among patients with clinical benefit from patients with favorable prognosis (OS 61 months, TTP 18 months, p &lt; 0.001), who had a truly negative model prediction. The possibility of prognosis improvement with therapy change was an essential factor for OS and TTP prediction (р &lt; 0.001). The model was useful in predicting higher OS in patients with disease progression (p = 0.033) and shorter response duration in patients with clinical benefit (р = 0.03). Conclusions: Our progression prediction model provides clinically useful information and can be used for decision making in several clinical situations. Its utility should be tested in a prospective trial.

HSD3B1 (1245A>C) polymorphism and clinical outcomes in metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone acetate (AA) and enzalutamide (ENZA): Results from two prospective studies.

5525 Background: The common HSD3B1 (1245A &gt; C) germline variant is associated with increased de-novo synthesis of androgens and worse outcomes in men treated with androgen-deprivation therapy in metastatic hormone sensitive prostate cancer. The aim of this study is to determine the role of this polymorphism on treatment outcomes for AA and ENZA in patients with mCRPC. Methods: A total of 547 patients treated with AA or ENZA for mCRPC from two prospective cohorts; cohort 1 included 202 from British Columbia (Canada) and cohort 2 enrolled 345 patients from the Spanish study PROREPAIR-B. HSD3B1 genotype was determined by targeted sequencing in cohort 1 and by Taqman SNP genotyping assay in cohort 2. Associations between HSD3B1 genotypes and (TTPP), time to progression (TTP) and overall survival (OS) were evaluated via univariate COX regression. Multivariate analysis was performed to determine the independent association of each covariate. Results: The proportions of patients with a homozygous wild-type HSD3B1 (AA), heterozygous (AC) and homozygous variant (CC) genotype were respectively 45.6%, 39.4% and 15%. As expected, known prognostic factors for mCRPC such as hemoglobin, alkaline phosphatase (ALP), LDH, PSA at baseline as well as site of metastasis were significantly associated with TTPP and TPP. In the combined cohort, HSD3B1 (CC) genotype was associated with worse TTP (HR 1.31, 95%CI 1.02-1.67, p = 0.032) and PSA response rates (48% for CC vs 62% and 65% for AA and AC, respectively (p = 0.019, χ²)). Similar trend was observed for TTPP (HR 1.28, 95%CI 0.99-1.66, p = 0.064). OS was not different among genotypes, but was significantly shorter for patients with CC genotype in cohort 1 (HR 1.97, 95%CI 1.14-3.40, p = 0.016). There was no association between HSD3B1 genotype and time to castration-resistance in either of the two cohorts. Multivariable analysis showed that LDH, ALP, hemoglobin and use of AA or ENZA as first-line therapy for mCRPC were independent prognostic factors for TTP and TTPP; non-significant association was observed for genotype and TTP. Conclusions: HSD3B1 homozygous variant genotype (CC) was associated with shorter TTP and lower PSA response rate in mCRPC patients treated with AA or ENZA. However, the CC genotype did not provide prognostic information beyond that conferred by standard clinical variables, suggesting that it may not be a suitable stand-alone biomarker in mCRPC.

Abstract P1-07-24: Evaluation of the prognostic value of all four HER family receptors in patients with metastatic breast cancer treated with trastuzumab: A hellenic cooperative oncology group (HeCOG) study

Abstract Background-aim: Metastatic breast cancer (MBC) is an incurable disease. Trastuzumab, a recombinant humanized monoclonal antibody, was found to significantly prolongsurvival of patients with metastatic HER2 over-expressing and/or amplified breast cancer. In the current study, we performed a complete analysis, with four different methods, of all four HER family receptors, in a series of patients with metastatic breast cancer treated with trastuzumab-based regimens and evaluated their prognostic value. Methods: Formalin-fixed paraffin-embedded tumor tissue samples were collected from 227 patients, considered to be HER2-positive when assessed at the local laboratories. We evaluated gene amplification, copy number variations (CNVs), transcriptional profiling and protein expression of all four HER family members. In addition, our analysis included the evaluation of several other factors by immunohistochemistry (IHC), such as pHER2Tyr1221/1222, pHER2Tyr877 and PTEN. Results: Central review of HER2 status by IHC and fluorescence in situ hybridization revealed that of the 227 patients, only 139 (61.2%) were truly HER2-positive. Regarding the 191 patients treated with trastuzumab as first-line therapy, median time to progression (TTP) was 15.3 months and 10.4 months for HER2-positive and HER2-negative participants, respectively. Median survival was 50.4 months for HER2-positive and 38.1 months for HER2-negative patients. In HER2-positive patients, high HER3 mRNA expression was of favorable prognostic significance for TTP and survival (HR=0.43, 95% CI 0.21-0.88, Wald's p=0.022 and HR=0.43, 95% CI 0.21-0.88, p=0.021, respectively), while EGFR copy gain and EGFR protein expression were associated with higher risk for disease progression in HER2-negative patients (HR=3.53, 95% CI 1.19-10.50, p=0.023 and HR=3.37, 95% CI 1.12-10.17, p=0.031, respectively). Positive HER3 protein expression was a favorable factor for TTP in HER2-negative patients (HR=0.43, 95% CI 0.22-0.84, p=0.014). In the multivariate analysis, only EGFR copy gain retained its prognostic significance for TTP in the HER2-negative population (HR=4.81, 95% CI 1.52-15.82, p=0.008), while none of the examined factorsretained their prognostic significance for TTP or survival in the HER2-positive subgroup. Conclusions: The present study suggests that EGFR copy gain represents a negative prognostic factor for TTP in HER2-negative patients with metastatic breast cancer. In addition, high HER3 mRNA expression appears to be of favorable prognostic significance for TTP and survival in HER2-positive patients. Given the small number of patients included in the current analysis and the retrospective nature of the study, our findings should be validated in larger cohorts. Citation Format: Koutras A, Kotoula V, Koliou G-A, Kouvatseas G, Christodoulou C, Pectasides D, Batistatou A, Bobos M, Tsolaki E, Papadopoulou K, Pentheroudakis G, Papakostas P, Pervana S, Petraki K, Chrisafi S, Razis E, Psyrri A, Bafaloukos D, Kalogeras KT, Kalofonos HP, Fountzilas G. Evaluation of the prognostic value of all four HER family receptors in patients with metastatic breast cancer treated with trastuzumab: A hellenic cooperative oncology group (HeCOG) study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-24.

Lenalidomide with dexamethasone treatment for relapsed/refractory myeloma patients in Korea—experience from 110 patients

We conducted a retrospective analysis of lenalidomide with dexamethasone for patients with relapsed/refractory multiple myeloma (RRMM) who were treated within the Korean patient access program. Lenalidomide has been approved for RRMM for several years in Europe and North America, but has not been accessible to Asian patients in the past. Between 2008 and 2012, 110 patients from 20 hospitals were enrolled. The overall response rate (ORR) was 43.6 % with 15.4 % of very good partial response (VGPR) or better. The median time to progression (TTP) in this heavily pretreated patient population was 8.0 months, and median overall survival (OS) was 23 months. Hematologic toxicities, fatigue, anorexia, and constipation were the most common adverse events. The number of previous treatment lines, previous exposure to thalidomide, refractoriness to thalidomide and bortezomib, pretreatment white blood cell count (WBC), platelet count, t(14;16), and 17p deletion were significant prognostic factors for TTP, and creatinine clearance, refractoriness to thalidomide and bortezomib, performance status, platelet count, and 17p deletion were significant for OS in univariate analysis. In multivariate analysis, WBC and platelet count were significant prognostic factors for TTP and performance status for OS. For Korean myeloma patients, lenalidomide showed considerable efficacy, and toxicities were comparable to the data published in Europe and North America.

Efficacy of trabectedin for advanced soft tissue sarcoma (ASTS): A retrospective single center analysis.

e21509 Background: Trabectedin (Yondelis) is the first marine-derived antineoplastic drug approved in Europe for the treatment of patients with recurrent ASTS or for patients unsuited to receive anthracyclines and ifosfamide. We retrospectively analyzed patients with ASTS treated with trabectedin from Nov. 2006 to April 2012. Methods: Trabectedin was given at the approved dose of 1.5 mg/m2as a 24-h infusion every 3 weeks. An analysis of response rate, time to progression (TTP) and overall survival (OS) and univariate analyses of prognostic factors were performed. Results: Overall,39 patients (24 men) with mostly high-grade (n=29) ASTS with a median age of 57 years (range 20-81) were analyzed. Most had L-type STS (leiomyosarcoma n=10; liposarcoma n=3), undifferentiated pleomorphic sarcoma (n=11), sarcoma NOS (n=5), or synovial STS (n=2). Eight had one of 6 very rare STS. At baseline patients had metastatic (n=21), bulky (n=4) or metastatic/bulky (n=14) disease and were pretreated with a median of 2 prior chemotherapy lines (range: 0-3; 4 patients received adjuvant chemotherapy only), including anthracycline-based chemotherapy (n=30), gemcitabine plus dacarbazine (GEM-DTIC; n=18), other (n=20). Patients received a median of 4 trabectedin cycles (range 1-34). Among 37 evaluable patients best responses as per RECIST were partial response (PR, n=7), stable disease (SD &gt;3 months, n=9, 5 had SD &gt;6 months) and disease progression (n=19), and 5 patients had a decrease in tumor density. Responses to trabectedin and GEM-DTIC did not exclude responses to the other regimen suggesting the feasibility of sequential treatment. After a median follow-up of 9.37 months, median TTP and OS were 4.4 months (95% CI: 3.5-5.4) and 9.7 months (95% CI: 4.5-14.9), respectively. Univariate analyses identified low/medium-grade STS and growth modulation index &gt;1.13 as favorable prognostic factors for TTP, and retroperitoneal/visceral localization, L-type and rare STS and low/medium-grade STS for OS. Conclusions: The results of this real-life retrospective analysis confirmed the findings of previous trials showing that trabectedin is active drug for ASTS.

Multiparameter flow cytometry for the identification of the Waldenström’s clone in IgM-MGUS and Waldenström’s Macroglobulinemia: new criteria for differential diagnosis and risk stratification

Although multiparameter flow cytometry (MFC) has demonstrated clinical relevance in monoclonal gammopathy of undetermined significance (MGUS)/myeloma, immunophenotypic studies on the full spectrum of Waldenström's Macroglobulinemia (WM) remain scanty. Herein, a comprehensive MFC analysis on bone marrow samples from 244 newly diagnosed patients with an immunoglobulin M (IgM) monoclonal protein was performed, including 67 IgM-MGUS, 77 smoldering and 100 symptomatic WM. Our results show a progressive increase on the number and light-chain-isotype-positive B-cells from IgM-MGUS to smoldering and symptomatic WM (P<.001), with only 1% of IgM-MGUS patients showing >10% B cells or 100% light-chain-isotype-positive B-cells (P<.001). Complete light-chain restriction of the B-cell compartment was an independent prognostic factor for time-to progression in smoldering WM (median 26 months; HR: 19.8, P=0.001) and overall survival in symptomatic WM (median 44 months; HR: 2.6, P=0.004). The progressive accumulation of light-chain-isotype-positive B-cells accompanied the emergence of a characteristic Waldenstrom's phenotype (CD22(+dim) / CD25+ /CD27+ / IgM+) that differed from other B-NHL by negative expression of CD5, CD10, CD11c or CD103. In contrast to myeloma, light-chain-isotype-positive plasma cells in IgM monoclonal gammopathies show otherwise normal antigenic expression. Our results highlight the potential value of MFC immunophenotyping for the characterization of the Waldenström's clone, as well as for the differential diagnosis, risk of progression and survival in WM.

Impact of smoking history on patient outcome following hepatic metastasectomy for colorectal cancer.

517 Background: Although it is clear that smoking increases perioperative risks associated with liver resection, there are also oncologic concerns associated with smoking. For example, nicotine induces CRC cell proliferation in vitro. We undertook a single institution retrospective analysis of pts outcome based on prior smoking history. Methods: Under an IRB-approved protocol, pts who underwent hepatic metastasectomy for treatment for CRC liver metastasis with curative intent at a single institution, from 2005 to 2009, were retrospectively evaluated for smoking history, time to progression (TTP), and overall survival (OS). Pts were analyzed as never smokers (A), ex-smokers (B), or current smokers and those who discontinued at the time of cancer diagnosis (C). Results: 350 pts outcomes were analyzed; their data is demonstrated in the table below. There were no difference in TTP or OS between group A and B (p = 0.346, p = 0.453 respectively). Pts in group A had a superior TTP and OS when compared to group C (p =0.002, p = 0.021 respectively). Patients in group B had a superior TTP when compared to group C (p =0.044), while a difference of OS was not found between the two groups (p =0.153). Conclusions: Smoking history is a negative prognostic factor for TTP in patients undergoing hepatic metastasecomy for CRC. Further studies are necessary to validate these preliminary findings. Active smokers who are candidates for hepatic metastasectomy for CRC should undergo nicotine cessation counseling and treatment. [Table: see text]

Phase II clinical trial with gemcitabine and paclitaxel sequential monotherapy as first-line treatment for advanced non-small-cell lung cancer (SLCG 01-04)

In advanced-stage (IIIB or IV) non-small-cell lung cancer (NSCLC), combination chemotherapy has demonstrated response rates of 20% and a 1-year survival rate of 30%. We conducted a multicentre, open-label, nonrandomised phase II trial to determine the efficacy and tolerability of sequential monotherapy with gemcitabine followed by paclitaxel in chemotherapy-naïve patients with advanced NSCLC. Between December 2002 and July 2004, the Spanish Lung Cancer Group (SLCG) conducted a study in which 34 patients with advanced (stage IIIB or IV) NSCLC received 1200 mg/m(2) of i.v. gemcitabine on days 1, 8 and 15 of each 28-day cycle for a total of 3 cycles followed by 100 mg/m(2) of weekly i.v. paclitaxel for a maximum of 8 weeks. If objective response or stable disease was achieved, 70 mg/m(2) of weekly i.v. paclitaxel was maintained until disease progression was evident or toxic effects were intolerable. Lung Cancer Symptom Scale (LCSS) analysis was performed. Baseline levels of serum VEGF, EGFR, telomerase reverse transcriptase (hTERT) and K-ras mutations were analysed. The primary endpoint was the objective response rate. The median age of the 34 patients who were enrolled was 67 years (range 46-77), but later 8 patients were excluded; 78.8% were men, 81.8% had performance status 1 and also 81.8% had metastatic disease at diagnosis. The objective response rate was 28% (95% CI, 14.2-47.8); the median overall survival was 7.2 months (95% CI, 2.1-12.3) and the median time to progression (TTP) was 3.1 months (95% CI, 2.5-5.3). Grade 3 or 4 drug-related haematological toxicities were observed in 6 patients. Patients with lower baseline serum VEGF levels had significantly longer survival. Sequential therapy with gemcitabine followed by paclitaxel was well tolerated with a low proportion of grade 3 or 4 adverse events, the absence of unexpected toxicity and with an improvement in quality of life. Unfortunately, the response rate did not meet the minimally required rate of 20% and the study was prematurely closed. VEGF was identified as a poor prognostic factor for TTP and survival.

Absolute lymphocyte count at time of radioimmunotherapy predicted time to progression in patients with relapsed follicular lymphomas

18505 Background: Besides radiation, the immunologic mechanisms of action of 90Y ibritumomab tiuxetan (Zevalin) radioimmunotherapy (RIT) have been attributed to complement mediated lysis and antibody-dependent cellular cytotoxicity (ADCC). We hypothesized that a stronger host immune system prior to Zevalin therapy for relapsed follicular (grade 1&amp;2) lymphomas (FL) would result in an improved time to progression (TTP). As a surrogate marker of host immune status, we studied absolute lymphocyte count (ALC) prior to Zevalin therapy and its impact on TTP in relapsed FL patients. Methods: Between 1996 and 2006, 75 patients with relapsed FL were treated with single agent Zevalin (0.4 mCi/kg, maximum of 32 mCi) at the Mayo Clinic. ALC was obtained from the complete blood cell count prior to RIT. Results: The median age of the cohort was 60 years (range, 29–82 years). 36% (27/75) patients were rituximab refractory. The median TTP in all patients was 6.4 months (range, 1–99+ months). Univariately, ALC as a continuous (HR = 0.448, p &lt; 0.006) or dichotomized [ALC = 1.0 x 109/l (HR = 0.684, p &lt; 0.007)] variable was identified as a prognostic factor for TTP. Superior TTP was observed with an ALC = 1.0 x 109/l (N = 32) compared with an ALC &lt; 1.0 x 109/l (N=43) (median: 12.4 months vs 6.5 months, respectively, p &lt; 0.007). Both groups were balanced in regard to the Follicular Lymphoma International Prognostic Index (FLIPI). ALC, as a continuous (HR = 0.507, p &lt; 0.02) or dichotomized [ALC = 1.0 x 109/l (HR = 0.697, p &lt; 0.01)] variable was identified as an independent prognostic factor for TTP in the multivariate analysis when compared with FLIPI. In the ALC = 1.0 x 109/l group, 14/32 (44%) of FL patients achieved a TTP = 12 months compared to only 7/43 (16%) in the ALC &lt; 1.0 x 109/l group, (p &lt; 0.02). Conclusions: This study supports our hypothesis that a higher ALC, as a marker of immune status of the patient, predicts longer TTP following Zevalin therapy in relapsed FL. No significant financial relationships to disclose.

N9741: Survival update and prognostic factor analysis of oxaliplatin (Ox) and irinotecan (Iri) combinations for metastatic colorectal cancer (MCRC)

4067 Background: N9741 randomized 1691 patients (pts) to seven 5FU, Ox and Iri containing regimens for MCRC. After 20.4 months median follow-up, FOLFOX and IROX improved time to progression (TTP) and overall survival (OS) compared to IFL. Here we update OS and TTP, and report an analysis of factors prognostic of pt outcome. Methods: 5 yr OS and TTP were calculated by Kaplan-Meier per treatment (rx) arm. Pt factors [rx arm, age, gender, prior adjuvant rx, body mass index (BMI), performance status (PS), number of disease sites (#sites), neutrophil count (ANC), hemoglobin, platelets, bilirubin, alkaline phosphatase (ALK), aspartate aminotransferase (AST)] were assessed for univariate association with OS, TTP, response rate (RR), and any grade =3 toxicity. Associated factors were included in multivariate Cox and logistic regression models. Results: After a median follow-up of 4.3 yrs, FOLFOX treated pts were more likely to live 5 yrs, 9.2% versus 5.4% for IROX (p=.016) and 3.8% for IFL (p&lt;.001). Median TTP was also significantly longer in the FOLFOX arm, 9.2 mo vs 6.5 mo for IROX (p=&lt;.001) and 6.0 mo for IFL (p=&lt;.001). The prognostic model found higher PS, ANC and ALK, and more disease sites were prognostic of worse OS (see table ). Age = 70 was associated with poorer survival (HR death 1.33, p=.03), but not TTP, RR, or grade =3 toxicity. FOLFOX rx was the most powerful prognostic factor for TTP and OS. The odds of grade =3 toxicity were significantly higher in FOLFOX treated pts (OR 1.65, p&lt;.001) and lower in men (OR .63, p&lt;.001). No significant interactions between rx arm and pt factors were present, suggesting no factor examined is predictive of rx-specific outcome. Conclusions: 9% 5 yr OS in MCRC pts treated with first-line FOLFOX sets a new benchmark. We confirmed pre-rx PS, WBC, and ALK are prognostic for OS, though FOLFOX rx was the strongest prognostic factor. No factor was associated with differential outcome or toxicity by rx arm, thus these factors cannot be used to guide rx selection. [Table: see text] [Table: see text]

Absolute lymphocyte count prior to rituximab therapy predicts time to progression in patients with follicular grade 1 lymphoma

7586 Background: The immunologic mechanisms of action of rituximab have been described as complement mediated lysis, vaccine like effect, antibody-dependent cellular cytotoxicity (ADCC) and the cellular microenvironment. We hypothesized that in the treatment of follicular grade 1 lymphoma (FL), the presence of a stronger host immune status prior to rituximab therapy would result in a prolonged time to progression (TTP). As a surrogate marker for immune status, we evaluated the absolute lymphocyte count (ALC) prior to rituximab treatment. Methods: Between 1996 and 2002, 1,104 consecutive FL patients were evaluated at Mayo Clinic Rochester. Of these patients, we retrospectively analyzed a group of all FL patients who received rituximab (375 mg/m2 once a week for four weeks) alone at any time during their lymphoma treatment at the Mayo Clinic (n=79). The primary end-point was to assess the impact of ALC just prior to rituximab therapy on TTP for FL. Results: The median age of the cohort was 56.6 years (range: 25–98 years). The median follow-up was 12.5 months (range: 1–76 months). An ALC count of ≥ 890 cells/μL prior to rituximab therapy predicted a longer TTP compared with an ALC &lt; 890 cells/μl (25 months versus 8 months, respectively, p &lt; 0.0124). A higher complete response rate was observed in the ALC ≥ 890 cells/μL group compared with the ALC &lt; 890 cells/μL group [15/40 (38%) vs 5/39 (13%), p &lt; 0.035]. The groups were balanced regarding the Follicular Lymphoma International Prognostic Index (FLIPI) (p = 0.794). Multivariate analysis demonstrated ALC ≥ 890 cells/μL prior to rituximab therapy as an independent prognostic factor for TTP when compared to hemoglobin, LDH, and Ann Arbor stage. The ALC was independent of the FLIPI in multivariate analysis. Conclusions: This data supports the hypothesis that a higher lymphocyte count, as a marker of the immune status of the patient, predicts for a longer TTP following rituximab therapy. No significant financial relationships to disclose.