Quadriparesis and paraparesis following chimeric antigen receptor T-cell therapy in children and adolescents.

ABSTRACT: Immune effector cell-associated neurotoxicity syndrome (ICANS) is a common but potentially severe adverse event associated with chimeric antigen receptor T-cell (CART) therapy, characterized by the development of acute neurologic symptoms following CART infusion. ICANS encompasses a wide clinical spectrum typified by mild to severe encephalopathy, seizures, and/or cerebral edema. As more patients have been treated with CART, new ICANS phenomenology has emerged. We present the clinical course of 5 children who developed acute onset of quadriparesis or paraparesis associated with abnormal brain and/or spine neuroimaging after infusion of CD19- or CD22-directed CART, adverse events not previously reported in children. Orthogonal data from autopsy studies, cerebrospinal fluid (CSF) flow cytometry, and CSF proteomics/cytokine profiling demonstrated chronic white matter destruction, but a notable lack of inflammatory pathologic changes and cell populations. Instead, children with quadriparesis or paraparesis post-CART therapy had lower levels of proinflammatory cytokines, such as interferon gamma, CCL17, CCL23, and CXCL10, than those who did not develop quadriparesis or paraparesis. Taken together, these findings imply a noninflammatory source of this newly described ICANS phenomenon in children. The pathophysiology of some neurologic symptoms following CART may therefore have a more complex etiology than exclusive T-cell activation and excessive cytokine production.

Reduced toxicity matched sibling bone marrow transplant results in excellent outcomes for severe congenital neutropenia.

Severe congenital neutropenia (SCN) is caused by germline mutations, most commonly in ELANE, impacting neutrophil maturation and leading to high risk of life-threatening infections. Most patients with ELANE-mutant SCN can achieve safe neutrophil counts with chronic Granulocyte-Colony Stimulating Factor (G-CSF). However, up to 10% of patients have neutropenia refractory to G-CSF and require allogeneic stem cell transplant. Traditional conditioning for these patients includes busulfan and cyclophosphamide which is associated with significant toxicities. We present five patients with SCN without myeloid malignancy transplanted using a reduced toxicity regimen of busulfan, fludarabine and thymoglobulin. 5 pediatric patients with SCN underwent matched sibling donor bone marrow transplant (MSD-BMT) between 2014-2022 on or per CHP14BT057 (NCT02928991), a prospective, single center trial testing elimination of cyclophosphamide from conditioning in pediatric patients with single lineage inherited BMF syndromes. All patients had MSDs and no evidence of MDS. Conditioning consisted of PK-adjusted busulfan, fludarabine, and thymoglobulin, with calcineurin inhibitor and mycophenolate mofetil GVHD prophylaxis. With median follow-up of 48.4 months, overall and event-free survival were 100%. There was no acute GVHD and one instance of chronic limited GVHD. Patients exhibited >95% donor myeloid chimerism at 5 years post-BMT. Two patients experienced CMV reactivation without end-organ disease, and no other viral reactivation or significant infections occurred. MSD-BMT with reduced toxicity myeloablation for SCN provides excellent outcomes while minimizing toxicity. These data suggest that busulfan, fludarabine, and ATG can be considered an efficacious, low-toxicity standard of care regimen for patients with SCN undergoing MSD-BMT.

Reinfusion of CD19 CAR T cells for relapse prevention and treatment in children with acute lymphoblastic leukemia.

ABSTRACT: Relapse after CD19-directed chimeric antigen receptor (CAR)-modified T cells remains a substantial challenge. Short CAR T-cell persistence contributes to relapse risk, necessitating novel approaches to prolong durability. CAR T-cell reinfusion (CARTr) represents a potential strategy to reduce the risk of or treat relapsed disease after initial CAR T-cell infusion (CARTi). We conducted a retrospective review of reinfusion of murine (CTL019) or humanized (huCART19) anti-CD19/4-1BB CAR T cells across 3 clinical trials or commercial tisagenlecleucel for relapse prevention (peripheral B-cell recovery [BCR] or marrow hematogones ≤6 months after CARTi), minimal residual disease (MRD) or relapse, or nonresponse to CARTi. The primary endpoint was complete response (CR) at day 28 after CARTr, defined as complete remission with B-cell aplasia. Of 262 primary treatments, 81 were followed by ≥1 reinfusion (investigational CTL019, n = 44; huCART19, n = 26; tisagenlecleucel, n = 11), representing 79 patients. Of 63 reinfusions for relapse prevention, 52% achieved CR (BCR, 15/40 [38%]; hematogones, 18/23 [78%]). Lymphodepletion was associated with response to CARTr for BCR (odds ratio [OR], 33.57; P = .015) but not hematogones (OR, 0.30; P = .291). The cumulative incidence of relapse was 29% at 24 months for CR vs 61% for nonresponse to CARTr (P = .259). For MRD/relapse, CR rate to CARTr was 50% (5/10), but 0/8 for nonresponse to CARTi. Toxicity was generally mild, with the only grade ≥3 cytokine release syndrome (n = 6) or neurotoxicity (n = 1) observed in MRD/relapse treatment. Reinfusion of CTL019/tisagenlecleucel or huCART19 is safe, may reduce relapse risk in a subset of patients, and can reinduce remission in CD19+ relapse.

Evaluation of Children with Malignancies for Blood and Marrow Transplantation: A Report from the ASTCT Committee on Practice Guidelines.

Evaluation of a candidate for hematopoietic cell transplantation (HCT) is a complex process with substantial intercenter variability. Although literature providing guidance for evaluating the eligibility of adults is well established, similar guidance for children is lacking. To address gaps between adult recommendations and the specific needs of children, we convened a panel of pediatric HCT experts from a wide geographic range of American Society of Transplantation and Cellular Therapy (ASTCT) member institutions to offer recommendations for pediatric-focused pre-HCT evaluation. In this report from the ASTCT Committee on Practice Guidelines, we present a practical framework for evaluating children with malignancies who are candidates for HCT. We also highlight key differences from adults and emphasize areas of unmet need that require additional research to delineate best practices.

Impact of poverty and neighborhood opportunity on outcomes for children treated with CD19-directed CAR T-cell therapy.

Children living in poverty experience excessive relapse and death from newly diagnosed acute lymphoblastic leukemia (ALL). The influence of household poverty and neighborhood social determinants on outcomes from chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory (r/r) leukemia is poorly described. We identified patients with r/r CD19+ ALL/lymphoblastic lymphoma treated on CD19-directed CAR T-cell clinical trials or with commercial tisagenlecleucel from 2012 to 2020. Socioeconomic status (SES) was proxied at the household level, with poverty exposure defined as Medicaid-only insurance. Low-neighborhood opportunity was defined by the Childhood Opportunity Index. Among 206 patients aged 1 to 29, 35.9% were exposed to household poverty, and 24.9% had low-neighborhood opportunity. Patients unexposed to household poverty or low-opportunity neighborhoods were more likely to receive CAR T-cell therapy with a high disease burden (>25%), a disease characteristic associated with inferior outcomes, as compared with less advantaged patients (38% vs 30%; 37% vs 26%). Complete remission (CR) rate was 93%, with no significant differences by household poverty (P = .334) or neighborhood opportunity (P = .504). In multivariate analysis, patients from low-opportunity neighborhoods experienced an increased hazard of relapse as compared with others (P = .006; adjusted hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.3-4.1). There was no difference in hazard of death (P = .545; adjusted HR, 1.2; 95% CI, 0.6-2.4). Among children who successfully receive CAR T-cell therapy, CR and overall survival are equitable regardless of proxied SES and neighborhood opportunity. Children from more advantaged households and neighborhoods receive CAR T-cell therapy with a higher disease burden. Investigation of multicenter outcomes and access disparities outside of clinical trial settings is warranted.

Unrelated donor α/ß T cell- and B cell-depleted HSCT for the treatment of pediatric acute leukemia.

Unrelated donor (URD) hematopoietic stem cell transplant (HSCT) is associated with an increased risk of severe graft-versus-host disease (GVHD). TCRαß/CD19 depletion may reduce this risk, whereas maintaining graft-versus-leukemia. Outcome data with TCRαß/CD19 depletion generally describe haploidentical donors, with relatively few URDs. We hypothesized that TCRαß/CD19-depletion would attenuate the risks of GVHD and relapse for URD HSCT. Sixty pediatric and young adult (YA) patients with hematologic malignancies who lacked a matched-related donor were enrolled at 2 large pediatric transplantation centers between October 2014 and September 2019. All patients with acute leukemia had minimal residual disease testing, and DP typing was available for 77%. All patients received myeloablative total body irradiation- or busulfan-based conditioning with no posttransplant immune suppression. Engraftment occurred in 98%. Four-year overall survival was 69% (95% confidence interval [CI], 52%-81%), and leukemia-free survival was 64% (95% CI, 48%-76%), with no difference between lymphoid and myeloid malignancies (P = .6297 and P = .5441, respectively). One patient (1.7%) experienced primary graft failure. Relapse occurred in 11 patients (3-year cumulative incidence, 21%; 95% CI, 11-34), and 8 patients (cumulative incidence, 15%; 95% CI, 6.7-26) experienced nonrelapse mortality. Grade III to IV acute GVHD was seen in 8 patients (13%), and 14 patients (26%) developed chronic GVHD, of which 6 (11%) had extensive disease. Nonpermissive DP mismatch was associated with higher likelihood of acute GVHD (odds ratio, 16.50; 95% CI, 1.67-163.42; P = .0166) but not with the development of chronic GVHD. URD TCRαß/CD19-depleted peripheral HSCT is a safe and effective approach to transplantation for children/YAs with leukemia. This trial was registered at www.clinicaltrials.gov as #NCT02323867.

Impact of high-risk cytogenetics on outcomes for children and young adults receiving CD19-directed CAR T-cell therapy.

Chimeric antigen receptor (CAR) T-cell therapy can induce durable remissions of relapsed/refractory B-acute lymphoblastic leukemia (ALL). However, case reports suggested differential outcomes mediated by leukemia cytogenetics. We identified children and young adults with relapsed/refractory CD19+ ALL/lymphoblastic lymphoma treated on 5 CD19-directed CAR T-cell (CTL019 or humanized CART19) clinical trials or with commercial tisagenlecleucel from April 2012 to April 2019. Patients were hierarchically categorized according to leukemia cytogenetics: High-risk lesions were defined as KMT2A (MLL) rearrangements, Philadelphia chromosome (Ph+), Ph-like, hypodiploidy, or TCF3/HLF; favorable as hyperdiploidy or ETV6/RUNX1; and intermediate as iAMP21, IKZF1 deletion, or TCF3/PBX1. Of 231 patients aged 1 to 29, 74 (32%) were categorized as high risk, 28 (12%) as intermediate, 43 (19%) as favorable, and 86 (37%) as uninformative. Overall complete remission rate was 94%, with no difference between strata. There was no difference in relapse-free survival (RFS; P = .8112), with 2-year RFS for the high-risk group of 63% (95% confidence interval [CI], 52-77). There was similarly no difference seen in overall survival (OS) (P = .5488), with 2-year OS for the high-risk group of 70% (95% CI, 60-82). For patients with KMT2A-rearranged infant ALL (n = 13), 2-year RFS was 67% (95% CI, 45-99), and OS was 62% (95% CI, 40-95), with multivariable analysis demonstrating no increased risk of relapse (hazard ratio, 0.70; 95% CI, 0.21-2.90; P = .7040) but a higher proportion of relapses associated with myeloid lineage switch and a 3.6-fold increased risk of all-cause death (95% CI, 1.04-12.75; P = .0434). CTL019/huCART19/tisagenlecleucel are effective at achieving durable remissions across cytogenetic categories. Relapsed/refractory patients with high-risk cytogenetics, including KMT2A-rearranged infant ALL, demonstrated high RFS and OS probabilities at 2 years.

CD19-targeted chimeric antigen receptor T-cell therapy for CNS relapsed or refractory acute lymphocytic leukaemia: a post-hoc analysis of pooled data from five clinical trials.

BACKGROUND: CNS relapse of acute lymphocytic leukaemia is difficult to treat. Durable remissions of relapsed or refractory B-cell acute lymphocytic leukaemia have been observed following treatment with CD19-directed chimeric antigen receptor (CAR) T cells; however, most trials have excluded patients with active CNS disease. We aimed to assess the safety and activity of CAR T-cell therapy in patients with a history of CNS relapsed or refractory B-cell acute lymphocytic leukaemia. METHODS: In this post-hoc analysis, we included 195 patients (aged 1-29 years; 110 [56%] male and 85 [44%] female) with relapsed or refractory CD19-positive acute lymphocytic leukaemia or lymphocytic lymphoma from five clinical trials (Pedi CART19, 13BT022, ENSIGN, ELIANA, and 16CT022) done at the Children's Hospital of Philadelphia (Philadelphia, PA, USA), in which participants received CD19-directed CAR T-cell therapy between April 17, 2012, and April 16, 2019. The trials required control of CNS disease at enrolment and infusion and excluded treatment in the setting of acute neurological toxic effects (>grade 1 in severity) or parenchymal lesions deemed to increase the risk of neurotoxicity. 154 patients from Pedi CART19, ELIANA, ENSIGN, and 16CT022 received tisagenlecleucel and 41 patients from the 13BT022 trial received the humanised CD19-directed CAR, huCART19. We categorised patients into two strata on the basis of CNS status at relapse or within the 12 months preceding CAR T-cell infusion-either CNS-positive or CNS-negative disease. Patients with CNS-positive disease were further divided on the basis of morphological bone marrow involvement-either combined bone marrow and CNS involvement, or isolated CNS involvement. Endpoints were the proportion of patients with complete response at 28 days after infusion, Kaplan-Meier analysis of relapse-free survival and overall survival, and the incidence of cytokine release syndrome and neurotoxicity. FINDINGS: Of all 195 patients, 66 (34%) were categorised as having CNS-positive disease and 129 (66%) as having CNS-negative disease, and 43 (22%) were categorised as having isolated CNS involvement. The median length of follow-up was 39 months (IQR 25-49) in the CNS-positive stratum and 36 months (18-49) in the CNS-negative stratum. The proportion of patients in the CNS-positive stratum with a complete response at 28 days after infusion was similar to that in the CNS-negative stratum (64 [97%] of 66 vs 121 [94%] of 129; p=0·74), with no significant difference in relapse-free survival (60% [95% CI 49-74] vs 60% [51-71]; p=0·50) or overall survival (83% [75-93] vs 71% [64-79]; p=0·39) at 2 years between the two groups. Overall survival at 2 years was significantly higher in patients with isolated CNS involvement compared with those with bone marrow involvement (91% [82-100] vs 71% [64-78]; p=0·046). The incidence and severity of neurotoxicity (any grade, 53 [41%] vs 38 [58%]; grade 1, 24 [19%] vs 20 [30%]; grade 2, 14 [11%] vs 10 [15%]; grade 3, 12 [9%] vs 6 [9%], and grade 4, 3 [2%] vs 2 [3%]; p=0·20) and cytokine release syndrome (any grade, 110 [85%] vs 53 [80%]; grade 1, 12 [9%] vs 2 [3%]; grade 2, 61 [47%] vs 38 [58%]; grade 3, 18 [14%] vs 7 [11%] and grade 4, 19 [15%] vs 6 [9%]; p=0·26) did not differ between the CNS-negative and the CNS-positive disease strata. INTERPRETATION: Tisagenlecleucel and huCART19 are active at clearing CNS disease and maintaining durable remissions in children and young adults with CNS relapsed or refractory B-cell acute lymphocytic leukaemia or lymphocytic lymphoma, without increasing the risk of severe neurotoxicity; although care should be taken in the timing of therapy and disease control to mitigate this risk. These preliminary findings support the use of these CAR T-cell therapies for patients with CNS relapsed or refractory B-cell acute lymphocytic leukaemia. FUNDING: Children's Hospital of Philadelphia Frontier Program.

Humanized CD19-Targeted Chimeric Antigen Receptor (CAR) T Cells in CAR-Naive and CAR-Exposed Children and Young Adults With Relapsed or Refractory Acute Lymphoblastic Leukemia.

PURPOSE: CD19-targeted chimeric antigen receptor (CAR)-modified T cells demonstrate unprecedented responses in B-cell acute lymphoblastic leukemia (B-ALL); however, relapse remains a substantial challenge. Short CAR T-cell persistence contributes to this risk; therefore, strategies to improve persistence are needed. METHODS: We conducted a pilot clinical trial of a humanized CD19 CAR T-cell product (huCART19) in children and young adults with relapsed or refractory B-ALL (n = 72) or B-lymphoblastic lymphoma (n = 2), treated in two cohorts: with (retreatment, n = 33) or without (CAR-naive, n = 41) prior CAR exposure. Patients were monitored for toxicity, response, and persistence of huCART19. RESULTS: Seventy-four patients 1-29 years of age received huCART19. Cytokine release syndrome developed in 62 (84%) patients and was grade 4 in five (6.8%). Neurologic toxicities were reported in 29 (39%), three (4%) grade 3 or 4, and fully resolved in all cases. The overall response rate at 1 month after infusion was 98% (100% in B-ALL) in the CAR-naive cohort and 64% in the retreatment cohort. At 6 months, the probability of losing huCART19 persistence was 27% (95% CI, 14 to 41) for CAR-naive and 48% (95% CI, 30 to 64) for retreatment patients, whereas the incidence of B-cell recovery was 15% (95% CI, 6 to 28) and 58% (95% CI, 33 to 77), respectively. Relapse-free survival at 12 and 24 months, respectively, was 84% (95% CI, 72 to 97) and 74% (95% CI, 60 to 90) in CAR-naive and 74% (95% CI, 56 to 97) and 58% (95% CI, 37 to 90) in retreatment cohorts. CONCLUSION: HuCART19 achieved durable remissions with long-term persistence in children and young adults with relapsed or refractory B-ALL, including after failure of prior CAR T-cell therapy.

Risk-Adapted Preemptive Tocilizumab to Prevent Severe Cytokine Release Syndrome After CTL019 for Pediatric B-Cell Acute Lymphoblastic Leukemia: A Prospective Clinical Trial.

PURPOSE: To prospectively evaluate the effectiveness of risk-adapted preemptive tocilizumab (PT) administration in preventing severe cytokine release syndrome (CRS) after CTL019, a CD19 chimeric antigen receptor T-cell therapy. METHODS: Children and young adults with CD19-positive relapsed or refractory B-cell acute lymphoblastic leukemia were assigned to high- (≥ 40%) or low- (< 40%) tumor burden cohorts (HTBC or LTBC) based on a bone marrow aspirate or biopsy before infusion. HTBC patients received a single dose of tocilizumab (8-12 mg/kg) after development of high, persistent fevers. LTBC patients received standard CRS management. The primary end point was the frequency of grade 4 CRS (Penn scale), with an observed rate of ≤ 5 of 15 patients in the HTBC pre-defined as clinically meaningful. In post hoc analyses, the HTBC was compared with a historical cohort of high-tumor burden patients from the initial phase I CTL019 trial. RESULTS: The primary end point was met. Seventy patients were infused with CTL019, 15 in the HTBC and 55 in the LTBC. All HTBC patients received the PT intervention. The incidence of grade 4 CRS was 27% (95% CI, 8 to 55) in the HTBC and 3.6% (95% CI, 0.4 to 13) in the LTBC. The best overall response rate was 87% in the HTBC and 100% in the LTBC. Initial CTL019 expansion was greater in the HTBC than the LTBC (P < .001), but persistence was not different (P = .73). Event-free and overall survival were worse in the HTBC (P = .004, P < .001, respectively). In the post hoc analysis, grade 4 CRS was observed in 27% versus 50% of patients in the PT and prior phase I cohorts, respectively (P = .18). CONCLUSION: Risk-adapted PT administration resulted in a decrease in the expected incidence of grade 4 CRS, meeting the study end point, without adversely impacting the antitumor efficacy or safety of CTL019.

Associations between genetic variants in folate and drug metabolizing pathways and relapse risk in pediatric acute lymphoid leukemia on CCG-1952.

Genetic variation in drug detoxification pathways may influence outcomes in pediatric acute lymphoblastic leukemia (ALL). We evaluated relapse risk and 24 variants in 17 genes in 714 patients in CCG-1961. Three TPMT and 1 MTR variant were associated with increased risks of relapse (rs4712327, OR 3.3, 95%CI 1.2-8.6; rs2842947, OR 2.7, 95%CI 1.1-6.8; rs2842935, OR 2.5, 95%CI 1.1-5.0; rs10925235, OR 4.9, 95%CI 1.1-25.1). One variant in SLC19A1 showed a protective effect (rs4819128, OR 0.5, 95%CI 0.3-0.9). Our study provides data that relapse risk in pediatric ALL is associated with germline variations in TPMT, MTR and SLC19A1.

TPMT and MTHFR genotype is not associated with altered risk of thioguanine-related sinusoidal obstruction syndrome in pediatric acute lymphoblastic leukemia: a report from the Children's Oncology Group.

Sinusoidal obstruction syndrome is a complication of therapy for pediatric ALL and may be modified by thiopurine methyltransferase activity as well as by MTHFR genotype. We assessed TPMT *3A, *3B, *3C, and MTHFR C677T and A1298C germline genetic polymorphisms among 351 patients enrolled in the thioguanine treatment arm of CCG-1952 clinical trial. TPMT and MTHFR C677T genotypes were not associated with SOS risk. The combination of MTHFR and TPMT variant genotypes was not associated with SOS risk. These suggest that germline genetic variation in TPMT and MTHFR do not significantly alter SOS risk in patients exposed to thioguanine.

Ethnic disparities in adjuvant chemotherapy for breast cancer are not caused by excess toxicity in black patients.

BACKGROUND: Black patients with breast cancer may be at greater risk for chemotherapy-related hematologic toxicity than white patients because of lower baseline blood cell counts. We hypothesize that these baseline differences could lead to excess hematologic toxicity and greater modification of chemotherapy dosing in black patients and that this may contribute to the poorer survival observed in black patients with breast cancer compared with white patients with breast cancer. PATIENTS AND METHODS: We performed a retrospective cohort study of black and white patients with breast cancer treated with adjuvant chemotherapy at an academic medical center over an 18-month period. Clinical chart review and pharmacy records were used to collect data on the following: modification of chemotherapy dose or administration; hematologic toxicity; blood cell counts before, during, and after therapy; occurrence of febrile neutropenia; use of prophylactic antibiotics; and use of granulocyte colony-stimulating factor in order to determine whether ethnicity was an independent predictor of these outcomes. RESULTS: Among 23 black patients and 98 white patients with breast cancer treated with adjuvant chemotherapy, modification of chemotherapy administration occurred in 56 patients (46%). Modification was more common among black patients (65.2% vs. 41.8%; relative risk [RR], 1.56; P = 0.04). Black patients were more likely to receive reduced cumulative doses of adjuvant chemotherapy (RR, 2.49; P = 0.03). CONCLUSION: Our findings suggest that hematologic tolerability of adjuvant chemotherapy is similar in black and white patients. Strategies aimed at improving psychosocial barriers to adjuvant therapy and at reducing surgical complications in black patients may improve overall breast cancer outcomes in this group.

Drug-metabolizing enzyme polymorphisms predict clinical outcome in a node-positive breast cancer cohort.

PURPOSE: Adjuvant chemotherapy cures only a subset of women with nonmetastatic breast cancer. Genotypes in drug-metabolizing enzymes, including functional polymorphisms in cytochrome P450 (CYP) and glutathione S-transferases (GST), may predict treatment-related outcomes. PATIENTS AND METHODS: We examined CYP3A4*1B, CYP3A5*3, and deletions in GST mu (GSTM1) and theta (GSTT1), as well as a priori-defined combinations of polymorphisms in these genes. Using a cohort of 90 node-positive breast cancer patients who received anthracycline-based adjuvant chemotherapy followed by high-dose multiagent chemotherapy with stem-cell rescue, we estimated the effect of genotype and other known prognostic factors on disease-free survival (DFS) and overall survival (OS). RESULTS: Patients who carried homozygous CYP3A4*1B and CYP3A5*3 variants and did not carry homozygous deletions in both GSTM1 and GSTT1 (denoted low-drug genotype group) had a 4.9-fold poorer DFS (P = .021) and a four-fold poorer OS (P = .031) compared with individuals who did not carry any CYP3A4*1B or CYP3A5*3 variants but had deletions in both GSTT1 and GSTM1 (denoted high-drug genotype group). After adjustment for other significant prognostic factors, the low-drug genotype group retained a significantly poorer DFS (hazard ratio [HR] = 4.9; 95% CI, 1.7 to 14.6; P = .004) and OS (HR = 4.8; 95% CI, 1.8 to 12.9; P = .002) compared with the high- and intermediate-drug combined genotype group. In the multivariate model, having low-drug genotype group status had a greater impact on clinical outcome than estrogen receptor status. CONCLUSION: Combined genotypes at CYP3A4, CYP3A5, GSTM1, and GSTT1 influence the probability of treatment failure after high-dose adjuvant chemotherapy for node-positive breast cancer.

Interleukin-6 -174G-->C polymorphism is associated with improved outcome in high-risk breast cancer.

Axillary lymph node involvement in breast cancer is a marker of recurrence risk. Despite aggressive adjuvant therapy, recurrence in patients with four or more involved lymph nodes approaches 50% at 5 years from diagnosis. Markers that can distinguish those likely to relapse from those likely to be cured are needed to tailor therapy and provide accurate prognostic information to patients. Although most work in this area has focused on tumor characteristics, we hypothesized that the host environment might also play a role in determining risk of relapse. We hypothesized that host inflammatory response, mediated in part by production of interleukin-6 (IL-6), might play a role in the elimination of microscopic residual tumor. Polymorphisms in the IL-6 promoter region appear to modulate serum levels of the cytokine via regulation of gene transcription. A single nucleotide polymorphism involving substitution of cytosine for guanine at position -174 has been associated with reduced transcription and improved outcome in a variety of nonmalignant diseases, including coronary artery disease and several autoimmune conditions. Tumor necrosis factor (TNF) alpha is a proinflammatory cytokine that also plays a role in regulating IL-6 transcription. We hypothesized that polymorphisms in IL-6 (-174 G>C) or TNF-alpha (G-238 or G-308) might be associated with prognosis in a subset of patients with high-risk breast cancer. Genotyping was performed on DNA from stored stem cells in 80 breast cancer patients diagnosed with at least four positive axillary lymph nodes at diagnosis who underwent anthracycline-based adjuvant chemotherapy followed by high-dose multiagent chemotherapy with stem cell rescue. Cox proportional hazards models were used to estimate the effect of genotype and other known prognostic factors on disease-free and overall survival (DFS and OS, respectively). The presence of at least one C allele in the IL-6 promoter at position -174 was significantly associated with both DFS and OS compared with G/G homozygotes. After adjustment for estrogen receptor (ER) status, number of involved lymph nodes, and tumor size, those patients carrying the G/G genotype had a 2.1-fold increase in the rate of failure and a 2.6-fold increase in the rate of death compared with carriers of any C allele at a mean follow-up of 55 months. ER status modulated the effect of IL-6 polymorphism: both DFS and OS were most favorable in patients who were carriers of any C-allele (G/C or C/C) and had ER-positive tumors. The presence of either G/G genotype or an ER-negative tumor increased the hazard of failure [hazard ratio (HR), 2.6 and 3.2, respectively] and death (HR, 2.0 and 2.2, respectively). The combination of both G/G genotype and ER-negative tumor resulted in an additional increase in the hazard of failure (HR, 5.4; four-group comparison, P = 0.003) and death (HR, 6.2; four-group comparison, P = 0.001). TNF-alpha -308 and -238 polymorphisms were not associated with variation in DFS or OS in this cohort. The IL-6-174 promoter polymorphism is associated with clinical outcome in this cohort of node-positive breast cancer patients who received high-dose adjuvant therapy. IL-6 genotype modulated the effect of ER status on outcome. These results support the hypothesis that IL-6 may play an important role in the control of micrometastatic disease in breast cancer. Additional studies are needed to confirm these results and elucidate the mechanisms responsible for these differences.