Spleen tyrosine kinase/FMS-like tyrosine kinase-3 inhibition in relapsed/refractory B-cell lymphoma, including diffuse large B-cell lymphoma: updated data with mivavotinib (TAK-659/CB-659)

We report an updated analysis from a phase I study of the spleen tyrosine kinase (SYK) and FMS-like tyrosine kinase 3 inhibitor mivavotinib, presenting data for the overall cohort of lymphoma patients, and the subgroup of patients with diffuse large B-cell lymphoma (DLBCL; including an expanded cohort not included in the initial report). Patients with relapsed/refractory lymphoma for which no standard treatment was available received mivavotinib 60-120 mg once daily in 28-day cycles until disease progression/unacceptable toxicity. A total of 124 patients with lymphoma, including 89 with DLBCL, were enrolled. Overall response rates (ORR) in response-evaluable patients were 45% (43/95) and 38% (26/69), respectively. Median duration of response was 28.1 months overall and not reached in DLBCL responders. In subgroups with DLBCL of germinal center B-cell (GCB) and non-GCB origin, ORR was 28% (11/40) and 58% (7/12), respectively. Median progression free survival was 2.0 and 1.6 months in the lymphoma and DLBCL cohorts, respectively. Grade ≥3 treatment-emergent adverse events occurred in 96% of all lymphoma patients, many of which were limited to asymptomatic laboratory abnormalities; the most common were increased amylase (29%), neutropenia (27%), and hypophosphatemia (26%). These findings support SYK as a potential therapeutic target for the treatment of patients with B-cell lymphomas, including DLBCL. Trial registration: ClinicalTrials.gov number: NCT02000934.

A phase 1b, multicenter, dose-escalation study of subasumstat (TAK-981) in combination with pembrolizumab in patients (pts) with advanced solid tumors

2506

Background: SUMOylation is a post-translational modification with a role in limiting type 1 interferon (IFN-1)-dependent immune responses. Subasumstat is a small-molecule inhibitor of SUMOylation with the potential to increase antitumor immunity and overcome tumor resistance to checkpoint inhibitors (CPI) by inducing IFN-1 signaling. Preclinical data suggest that subasumstat enhances antigen cross-presentation, promoting T cell dependent antitumor responses; subasumstat plus an anti-PD-1 CPI has shown synergistic tumor growth inhibition and activation of CD8+ T cells and natural killer cells in syngeneic mouse models. We report data from the dose escalation part of a phase 1b study of subasumstat with pembrolizumab in pts with relapsed/refractory, CPI-exposed, non-squamous non-small-cell lung cancer (NSCLC) or microsatellite-stable colorectal cancer (MSS-CRC). Methods: Pts received escalating doses (40, 60, 90, and 120 mg) of subasumstat IV in 3 dosing schedules: days 1 and 8 (QW), days 1, 4, 8, and 11 (BIW), or days 1, 8, and 15 (90 mg only) of 21-day cycles, plus pembrolizumab 200 mg IV on day 1 of each cycle for 2 years or until disease progression or unacceptable toxicity. Dose escalation was guided by Bayesian optimal interval design. Phase 1b primary objectives were safety, tolerability, and the recommended phase 2 dose of subasumstat with pembrolizumab. Results: As of October 13, 2021, 43 (35 MSS-CRC; 8 NSCLC) pts had received ≥1 dose of subasumstat (22 BIW [40–120 mg]; 15 QW [90 –120 mg]; 6 on days 1, 8, 15 [90 mg)]. Median number of treatment cycles was 3; 28 (65%) pts had discontinued treatment, 21 (49%) due to progressive disease. Median age was 58 years (range 34–77); 56% of pts were male. One pt had a dose-limiting toxicity of grade 3 angioedema at 120 mg BIW. The maximum tolerated dose was not identified. Treatment-emergent adverse events (TEAEs) occurred in 38 (88%) pts; subasumstat-related TEAEs occurred in 34 (79%) pts, and included chills in 20 (47%), pyrexia in 16 (37%), fatigue in 9 (21%), anemia in 6 (14%), and stomatitis in 5 pts (12%; 3 [50%] in the 120 mg BIW cohort). Grade ≥3 TEAEs occurred in 24 (56%) pts; subasumstat-related grade ≥3 TEAEs reported in 10 (23%) pts included anemia, pyrexia, and increased aspartate aminotransferase (2 [5%] pts each). Pharmacokinetic activity of subasumstat was linear and decreased in a tri-phasic manner. Subasumstat exerted pharmacodynamic activity including target engagement, SUMOylation inhibition and increased IFN-1 signaling. Partial responses were observed at ≥40 mg dose levels in pts with NSCLC and MSS-CRC. Conclusions: Subasumstat plus pembrolizumab showed a favorable safety profile and promising anti-tumor activity in pre-treated NSCLC and MSS-CRC pts. Updated data will be presented at the meeting. Subasumstat plus pembrolizumab is currently in phase 2 clinical development (NCT04381650). Clinical trial information: NCT04381650.

476 First-in-human phase 1/2 study of the first-in-class SUMO-activating enzyme inhibitor TAK-981 in patients with advanced or metastatic solid tumors or relapsed/refractory lymphoma: phase 1 results

Background

SUMOylation is a post-translational modification that serves as an important modulator of immune responses via its role in constraining the type I interferon (IFN-1) response. TAK-981 is a small molecule that inhibits SUMOylation and increases IFN-1-dependent innate immune responses with the potential to enhance adaptive immunity. Here, we report dose-escalation data from a TAK-981 Phase 1/2 clinical study (NCT03648372), the first clinical data for a SUMOylation inhibitor.

Methods

Adults with advanced/metastatic solid tumors or relapsed/refractory lymphomas received TAK-981 IV twice-weekly (BIW; days 1, 4, 8, 11) or once-weekly (QW; days 1, 8) in 21-day cycles. Dose escalation was guided by a Bayesian Logistic Regression Model (BLRM) with overdose control, plus available pharmacokinetic/pharmacodynamic (PK/PD) data. Phase 1 objectives were to determine TAK-981 safety/tolerability and establish the recommended phase 2 dose (RP2D).

Results

Seventy-six patients received TAK-981 at 10 dose levels (3–40 mg BIW; 60–120 mg QW/BIW). Median age was 61 years (range, 38–79); 42 (55.3%) patients were female. Four dose-limiting toxicities were seen in 62 evaluable patients (transient grade 3 ALT/AST elevation, 60 mg BIW; grade 3 pneumonitis, 90 mg BIW; grade 3 stomatitis and grade 3 cognitive disturbance, 120 mg BIW). Per BLRM, 120 mg BIW was determined to be the maximum tolerated dose. At data cut-off, median treatment duration was 2 cycles (range, 1–12); 13 (17.1%) patients were ongoing. table 1 summarizes TAK-981 safety. The most common (≥20%) treatment-emergent adverse events (TEAEs) were fatigue (42.1%), nausea (39.5%), headache (31.6%), diarrhea (28.9%), pyrexia (27.6%), vomiting (23.7%), decreased appetite (22.4%). Common (≥5%) grade ≥3 TEAEs were hypokalemia (9.2%), anemia (7.9%), lymphocyte count decreased (6.6%), abdominal pain (5.3%). Grade 2 cytokine release syndrome was reported in 4 (5.2%) patients; symptoms resolved within 12–24 hours with supportive oxygen and/or IV fluids. One partial response was observed at 40 mg TAK-981 BIW in a patient with relapsed/refractory HER2-negative, hormone receptor-positive breast cancer. TAK-981 exhibited linear PK, with approximately dose-proportional exposure and a mean terminal half-life of 3.8–10.8 hours at ≥60 mg. Evidence of dose-dependent target engagement (figure 1), and PD (figures 2–4) in blood were observed. The single-agent TAK-981 RP2D was 90 mg BIW.

Abstract 476 Table 1

Summary of TAK-981 safety profile

Abstract 476 Figure 1

PD in patients receiving TAK-981 on the BIW schedule: target engagement.

Blood samples were collected on Cycle 1 Day 1 pre-dose and at multiple timepoints after TAK-981 administration. Target engagement in T cells was detected by flow cytometry with an antibody recognizing the TAK-981-SUMO adduct formed during the inhibition of the SUMO-activating enzyme by TAK-981; Cycle 1 Day 1 signal increased at 1 hour post-end-of-infusion compared to the background level observed pre-dose.

Abstract 476 Figure 2

PD in patients receiving TAK-981 on the BIW schedule: SUMOylation.

SUMOylation in T cells, detected by flow cytometry with an antibody recognizing SUMO2/3, decreased at 1 hour post-end-of-infusion on Cycle 1 Day 1 compared to pre-dose, indicating that fewer SUMO2/3 chains are formed when the SUMO-activating enzyme is inhibited.

Abstract 476 Figure 3

PD in patients receiving TAK-981 on the BIW schedule: upregulation of CXCL10 expression.

Upregulation of mRNA levels of CXCL10, an IFN-I-regulated gene, in peripheral blood. Gene expression was measured using Nanostring nCounter at Cycle 1 Day 1 pre-dose and at several timepoints post-dose. Data for maximum increase at 8 or 24 hours, relative to pre-dose, is shown.

Abstract 476 Figure 4

PD in patients receiving TAK-981 on the BIW schedule: NK cell activation.

NK cell activation in peripheral blood measured by flow cytometry. Percentage of CD69-positive NK cells at Cycle 1 Day 1 pre-dose and at 24 hours post-end-of-infusion is shown by patient for each dose.

Conclusions

The data generated in this study support continued TAK-981 development for treatment of solid tumors and lymphoma. The Phase 2 study expansion is ongoing in patients with advanced/metastatic non-small-cell lung, cervical, and colorectal cancer, and in relapsed/refractory non-Hodgkin lymphoma.

Trial Registration

Clinical Trial identification:

ClinicalTrials.gov. Identifier: NCT03648372

Ethics Approval

The study was approved by the Institutional Review Board or Institutional Ethics Committee of all participating institutions

Phase 1/2 study of the novel SUMOylation inhibitor TAK-981 in adult patients (pts) with advanced or metastatic solid tumors or relapsed/refractory (RR) hematologic malignancies

TPS2667

Background: SUMOylation, a posttranslational modification analogous to ubiquitination, attaches a small, ubiquitin-like modifier (SUMO) to target proteins. SUMOylation plays a central role in regulating type I interferon (IFN-I)-dependent innate response and functions to constrain the innate immune response, which can impair tumor immune surveillance. TAK-981 is a first-in-class, small-molecule inhibitor of SUMO-activating enzyme subunit 2 (SAE2). Inhibition of SAE2 by TAK-981 disrupts SUMOylation, thereby allowing innate immune system activation. In ex vivo assays, TAK-981 increased phagocytic activity of monocyte-derived macrophages, increased natural killer cell cytotoxicity, and induced markers of dendritic cell activation and maturation via IFN-I signaling. In syngeneic mouse models, TAK-981 resulted in antitumor activity, including complete remissions, and a sustained, protective antitumor immune response. Methods: This first-in-human study of single-agent TAK-981 comprises two parts. Phase 1 primary objectives are to determine safety and tolerability, and to select a recommended phase 2 dose (RP2D); secondary objectives are to assess preliminary antitumor activity, characterize pharmacokinetics (PK), and explore pharmacodynamic (PD) biomarkers. This phase will enroll ̃70 pts with untreatable locally advanced or metastatic solid tumors or RR lymphoma. The phase 2 primary objective is to evaluate preliminary efficacy at the RP2D in ̃132 pts with non-squamous non-small cell lung cancer, cervical cancer, microsatellite-stable colorectal cancer, or CD20+ RR diffuse large B-cell lymphoma or follicular lymphoma. Pts receive TAK-981 via a 1-hour intravenous infusion on days 1, 4, 8, and 11 in 21-day cycles until unacceptable toxicity, pt withdrawal, or death. Dose escalation is proceeding from 3 mg, guided by an adaptive 3+3 design combined with Bayesian logistic regression modelling with overdose control, plus consideration of other safety, clinical, PK, and PD data. The RP2D will be based on the maximum tolerated dose (MTD) or on a biologically effective dose (BED) that is ≤MTD. The BED is defined as a dose at which there is evidence of drug-target engagement and inhibition of SUMOylation, plus: induction of cytokines/chemokines and/or IFN-I signature in tumor or blood; evidence of increased T cell infiltration in tumor; or antitumor activity. PK/PD modeling in the BED range is ongoing and will be used in RP2D determination. Clinical trial information: NCT03648372.

Total mesorectal excision and sphincter preservation — the early steps of rectal cancer surgery

The treatment of rectal cancer has evolved significantly over the last 100 years. Standardization of total mesorectal excision and the development of techniques for sphincter preservation have resulted in significant improvements in the management of this disease. Still, local disease control and functional outcomes of sphincter preserving procedures remain a relevant issue. In this historical paper, the oncological and functional outcomes of patients with rectal cancer treated between 1960 and 1971 by a pioneer woman surgeon using a sphincter preserving approach and a technique resembling total mesorectal excision performed at that time are reported. The results reflect one of the earliest steps of partial intersphincteric resection and total mesorectal excision with good oncological outcomes (2% local recurrence) and acceptable functional outcomes in a highly selected group of patients.

Consolidation chemotherapy during neoadjuvant chemoradiation (CRT) for distal rectal cancer leads to sustained decrease in tumor metabolism when compared to standard CRT regimen

Background

Neoadjuvant CRT may lead to significant tumor regression in patients with rectal cancer. Different CRT regimens with consolidation chemotherapy may lead to increased rates of complete tumor regression. The purpose of this study was to understand tumor metabolic activity following two different neoadjuvant CRT regimens using sequential PET/CT imaging in two different intervals following RT.

Methods

Patients with cT2-4 N0-2 M0 rectal cancer treated by standard CRT (54Gy and 2 cycles of 5FU-based chemotherapy) or extended CRT (54Gy and 6 cycles of 5FU-based chemotherapy) underwent sequential PET/CT imaging at baseline, 6 weeks and 12 weeks from radiation completion.

Results

99 patients undergoing standard CRT were compared to 12 patients undergoing CRT with consolidation chemotherapy. Patients treated with consolidation CRT had increased rates of complete clinical or pathological response (66 % vs. 23 %; p < 0.001). SUVmax variation between baseline and 6 weeks (88 % vs. 63 %; p < 0.001) and between baseline and 12 weeks (90 % vs. 57 %; p < 0.001) were significantly more pronounced among patients undergoing extended CRT with consolidation chemotherapy. An increase in SUVmax between 6 and 12 weeks was observed in 51 % of patients undergoing standard and 18 % of patients undergoing consolidation CRT (p = 0.04).

Conclusions

Most of the reduction in tumor metabolism after neoadjuvant CRT occurs within the first 6 weeks from RT completion. In patients undergoing CRT with consolidation chemotherapy, tumors are less likely to regain metabolic activity between 6 and 12 weeks. Therefore, assessment of tumor response may be safely postponed to 12 weeks in patients undergoing extended CRT with consolidation chemotherapy.

Trial registration

NCT00254683

Transanal Endoscopic Microsurgery (TEM) Following Neoadjuvant Chemoradiation for Rectal Cancer: Outcomes of Salvage Resection for Local Recurrence

BACKGROUND

Transanal endoscopic microsurgery (TEM) has been considered an alternative for selected patients with rectal cancer following neoadjuvant chemoradiation (CRT). Immediate total mesorectal completion for all patients with unfavorable pathological features would result in unnecessary protectomies in a significant proportion of patients. Instead, salvage total mesorectal excision (TME) could be restricted for patients developing local recurrence. The aim of the present study is to determine oncological outcomes of salvage resection for local recurrences following CRT and TEM.

METHODS

Consecutive patients undergoing TEM following neoadjuvant CRT for rectal cancer were reviewed. Patients with "near" complete response to CRT (≤3 cm; ycT1-2N0) were offered TEM. Salvage surgery was attempted in the event of a local recurrence.

RESULTS

A total of 53 patients were managed by CRT followed by TEM. Unfavorable pathological features were present in 36 patients (68 %). None of the patients underwent immediate completion TME. There were 12 patients who developed local recurrence resulting in a 2-year local recurrence-free survival of 77 % (95 % CI, 53-100 %). Of these patients, 9 developed exclusively local recurrences, and all had at least 1 unfavorable pathological feature in the specimen after TEM (100 %). Eight patients (8 of 9) underwent salvage resection (abdominoperineal resection [APR] in 87 %) with CRM+ in 7 of 8 patients (87 %). Four patients developed local re-recurrence after a median 36 months of follow-up. The 2-year local re-recurrence free survival was 60 %.

CONCLUSIONS

Salvage resection for local recurrence following CRT and TEM is associated with high rates of R1 resection (CRM+) and local re-recurrence. Immediate completion of TME should be considered for patients with unfavorable pathological features after TEM.

Transanal local excision for distal rectal cancer and incomplete response to neoadjuvant chemoradiation - does baseline staging matter?

BACKGROUND

Local excision may offer the possibility of organ preservation for the management of select patients after neoadjuvant chemoradiation. The oncological outcomes of this strategy have been largely associated with the risk of nodal metastases. Therefore, in addition to final ypT status, baseline staging has been suggested to potentially influence the outcomes of this treatment modality.

OBJECTIVE

The aim of this study is to compare the pathological and oncological outcomes of patients following neoadjuvant chemoradiation and incomplete clinical response managed by transanal endoscopic microsurgery according to baseline staging.

DESIGN

This study is a retrospective review of prospectively collected data.

SETTINGS

The study was conducted at a single center.

PATIENTS

Forty-six patients with distal rectal cancer cT2-4N0-2M0 underwent 5-fluorouracil-based neoadjuvant chemoradiation. Assessment of response was performed at least 8 weeks from radiotherapy completion. Patients with a complete clinical response were not operated on immediately. Patients with an incomplete clinical response were managed by surgery. Those with small (≤3 cm) residual cancers (ycT1-2N0M0) were managed by transanal endoscopic microsurgery.

MAIN OUTCOME MEASURES

Patients undergoing local excision following chemoradiation were compared according to baseline staging.

RESULTS

Fifteen patients (32%) were cT2N0 at baseline. Final ypT status was ypT0 in 3 (20%) patients, ypT1 in 2 (13%) patients, ypT2 in 9 (60%) patients, and ypT3 in 1 (7%) patient. There were no differences in final ypT status in comparison with patients with baseline cT3-4 or cN+ undergoing chemoradiation followed by transanal endoscopic microsurgery (p = 0.38). Local recurrence was observed in 1 patient with baseline cT2N0 (7%) and in 7 patients (23%) with stage II and III (p = 0.18).

LIMITATIONS

This study was limited by the short follow-up, its limited sample size, and its retrospective and nonrandomized nature.

CONCLUSIONS

Patients with baseline cT2N0 that do not develop complete response to chemoradiation (ycT0-2N0; ≤3 cm) frequently present unfavorable pathological features for transanal local excision (ypT2 or 3 in >66%). In the presence of incomplete clinical response following chemoradiation, patients with baseline cT2N0 have pathological and oncological outcomes similar to patients with baseline stage II or III and are probably not ideal candidates for local excision (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A159).

Clinical relevance of positron emission tomography/computed tomography-positive inguinal nodes in rectal cancer after neoadjuvant chemoradiation

AIM

Inguinal nodes may be a possible route for lymphatic spread in patients with distal rectal cancer. The outcome was examined for patients with distal rectal cancer undergoing neoadjuvant chemoradiation (CRT) and having 2-fluorine-18-fluoro-2-deoxy-d-glucose (FDG)-avid inguinal nodes using positron emission tomography/computed tomography (PET/CT) imaging.

METHOD

Ninety-nine consecutive patients with cT2-4N0-2M0 distal rectal adenocarcinoma were enrolled in a clinical trial (NCT00254683) and underwent baseline PET/CT followed by 54 Gy and 5-fluorouracil-based CRT. After CRT, patients underwent 6- and 12-week PET/CT. Patients with positive inguinal node uptake were compared with patients with negative uptake. The inguinal region was not included in the field of radiation therapy.

RESULTS

Seventeen (17%) patients had baseline positive inguinal node FDG uptake. They were more likely to have the tumour closer to the anal verge (2.0 vs 4.2 cm; P = 0.001). Of these, eight (47%) demonstrated a positive inguinal uptake at PET/CT after 12 weeks from CRT. Patients with inguinal node FDG uptake after CRT (positive PET at baseline and 12 weeks) had a significantly worse 3-year overall and disease-free survival (P = 0.02 and P = 0.03). After a median follow-up period of 22 months, none of these patients had developed inguinal recurrence.

CONCLUSION

Uptake of inguinal nodes at PET/CT may be present in up to 17% of patients with distal rectal cancer, particularly with ultra-low tumours. Nearly half of these nodes no longer show uptake after CRT despite the groin area not being included in the radiation field. Persistence of inguinal node uptake 12 weeks after CRT completion may be a marker for worse oncological outcome.

Role of biopsies in patients with residual rectal cancer following neoadjuvant chemoradiation after downsizing: can they rule out persisting cancer?

AIM

The study aimed to determine the value of postchemoradiation biopsies, performed after significant tumour downsizing following neoadjuvant therapy, in predicting complete tumour regression in patients with distal rectal cancer.

METHOD

A retrospective comparative study was performed in patients with rectal cancer who achieved an incomplete clinical response after neoadjuvant chemoradiotherapy. Patients with significant tumour downsizing (> 30% of the initial tumour size) were compared with controls (< 30% reduction of the initial tumour size). During flexible proctoscopy carried out postchemoradiation, biopsies were performed using 3-mm biopsy forceps. The biopsy results were compared with the histopathological findings of the resected specimen. UICC (Union for International Cancer Control) ypTNM classification, tumour differentiation and regression grade were evaluated. The main outcome measures were sensitivity and specificity, negative and positive predictive values, and accuracy of a simple forceps biopsy for predicting pathological response after neoadjuvant chemoradiotherapy.

RESULTS

Of the 172 patients, 112 were considered to have had an incomplete clinical response and were included in the study. Thirty-nine patients achieved significant tumour downsizing and underwent postchemoradiation biopsies. Overall, 53 biopsies were carried out. Of the 39 patients who achieved significant tumour downsizing, the biopsy result was positive in 25 and negative in 14. Only three of the patients with a negative biopsy result were found to have had a complete pathological response (giving a negative predictive value of 21%). Considering all biopsies performed, only three of 28 negative biopsies were true negatives, giving a negative predictive value of 11%.

CONCLUSION

In patients with distal rectal cancer undergoing neoadjuvant chemoradiation, post-treatment biopsies are of limited clinical value in ruling out persisting cancer. A negative biopsy result after a near-complete clinical response should not be considered sufficient for avoiding a radical resection.

Optimal timing for assessment of tumor response to neoadjuvant chemoradiation in patients with rectal cancer: do all patients benefit from waiting longer than 6 weeks?

PURPOSE

To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-d-glucose-labeled positron emission tomography/computed tomography ([(18)FDG]PET/CT) imaging and correlate with response to CRT.

METHODS AND MATERIALS

Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials.org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks from CRT completion). Clinical assessment was at 12 weeks. Maximal standard uptake value (SUVmax) of the primary tumor was measured and recorded at each PET/CT study after 1 h (early) and 3 h (late) from (18)FDG injection. Patients with an increase in early SUVmax between 6 and 12 weeks were considered "bad" responders and the others as "good" responders.

RESULTS

Ninety-one patients were included; 46 patients (51%) were "bad" responders, whereas 45 (49%) patients were "good" responders. "Bad" responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; P=.001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; P=.008) and exhibited greater final tumor dimension (4.3 cm vs. 3.3 cm; P=.03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CT was a significant predictor of "good" response (accuracy of 67%).

CONCLUSIONS

Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients.

Accuracy of positron emission tomography/computed tomography and clinical assessment in the detection of complete rectal tumor regression after neoadjuvant chemoradiation: long-term results of a prospective trial (National Clinical Trial 00254683)

BACKGROUND

Neoadjuvant chemoradiation (CRT) therapy may result in significant tumor regression in patients with rectal cancer. Patients who develop complete tumor regression have been managed by treatment strategies that are alternatives to standard total mesorectal excision. Therefore, assessment of tumor response with positron emission tomography/computed tomography (PET/CT) after neoadjuvant treatment may offer relevant information for the selection of patients to receive alternative treatment strategies.

METHODS

Patients with clinical T2 (cT2) through cT4NxM0 rectal adenocarcinoma were included prospectively. Neoadjuvant therapy consisted of 54 grays of radiation and 5-fluorouracil-based chemotherapy. Baseline PET/CT studies were obtained before CRT followed by PET/CT studies at 6 weeks and 12 weeks after the completion of CRT. Clinical assessment was performed at 12 weeks after CRT completion. PET/CT results were compared with clinical and pathologic data.

RESULTS

In total, 99 patients were included in the study. Twenty-three patients were complete responders (16 had a complete clinical response, and 7 had a complete pathologic response). The PET/CT response evaluation at 12 weeks indicated that 18 patients had a complete response, and 81 patients had an incomplete response. There were 5 false-negative and 10 false-positive PET/CT results. PET/CT for the detection of residual cancer had 93% sensitivity, 53% specificity, a 73% negative predictive value, an 87% positive predictive value, and 85% accuracy. Clinical assessment alone resulted in an accuracy of 91%. PET/CT information may have detected misdiagnoses made by clinical assessment alone, improving overall accuracy to 96%.

CONCLUSIONS

Assessment of tumor response at 12 weeks after CRT completion with PET/CT imaging may provide a useful additional tool with good overall accuracy for the selection of patients who may avoid unnecessary radical resection after achieving a complete clinical response. Cancer 2012;3501-3511. © 2011 American Cancer Society.

Transanal endoscopic microsurgery for residual rectal cancer after neoadjuvant chemoradiation therapy is associated with significant immediate pain and hospital readmission rates

BACKGROUND

Transanal endoscopic microsurgery may represent appropriate diagnostic and therapeutic procedure in selected patients with distal rectal cancer following neoadjuvant chemoradiation. Even though this procedure has been associated with low rates of postoperative complications, patients undergoing neoadjuvant chemoradiation seem to be at increased risk for suture line dehiscence. In this setting, we compared the clinical outcomes of patients undergoing transanal endoscopic microsurgery with and without neoadjuvant chemoradiation.

METHODS

Thirty-six consecutive patients were treated by transanal endoscopic microsurgery at a single institution. Twenty-three patients underwent local excision after neoadjuvant chemoradiation therapy for rectal adenocarcinoma, and 13 patients underwent local excision without any neoadjuvant treatment for benign and malignant rectal tumors. Chemoradiation therapy included 50.4 to 54 Gy and 5-fluorouracil-based chemotherapy. All patients underwent transanal endoscopic microsurgery with primary closure of the rectal defect. Complications (immediate and late) and readmission rates were compared between groups.

RESULTS

Overall, median hospital stay was 2 days. Immediate (30-d) complication rate was 44% for grade II/III complications. Patients undergoing neoadjuvant chemoradiation therapy were more likely to develop grade II/III immediate complications (56% vs 23%; P = .05). Overall, the 30-day readmission rate was 30%. Wound dehiscence was significantly more frequent among patients undergoing neoadjuvant chemoradiation therapy (70% vs 23%; P = .03). Patients undergoing neoadjuvant chemoradiation therapy were at significantly higher risk of requiring readmission (43% vs 7%; P = .02).

CONCLUSION

Transanal local excision with the use of endoscopic microsurgical approach may result in significant postoperative morbidity, wound dehiscence, and readmission rates, in particular, because of rectal pain secondary to wound dehiscence. In this setting, the benefits of this minimally invasive approach either for diagnostic or therapeutic purposes become significantly restricted to highly selected patients that can potentially avoid a major operation but will still face a significantly morbid and painful procedure.

Complete clinical response after neoadjuvant chemoradiation for distal rectal cancer

Multimodality treatment of rectal cancer, with the combination of radiation therapy, chemotherapy, and surgery has become the preferred approach to locally advanced rectal cancer. The use of neoadjuvant chemoradiation therapy (CRT) has resulted in reduced toxicity rates, significant tumor downsizing and downstaging, better chance of sphincter preservation, and improved functional results. A proportion of patients treated with neoadjuvant CRT may ultimately develop complete clinical response. Management of these patients with complete clinical response remains controversial and approaches including radical resection, transanal local excision, and observation alone without immediate surgery have been proposed. The use of strict selection criteria of patients after neoadjuvant CRT has resulted in excellent long-term results with no oncological compromise after observation alone in patients with complete clinical response. Recurrences are detectable by clinical assessment and frequently amenable to salvage procedures.

Lymph node size in rectal cancer following neoadjuvant chemoradiation--can we rely on radiologic nodal staging after chemoradiation?

OBJECTIVES

Local excision is currently being considered as an alternative strategy for ypT0-2 rectal cancer. However, patient selection is crucial to rule out nodal disease and is performed by radiologic studies that consider size as a surrogate marker for positive nodes. The purpose of this study was to determine the difference in size between metastatic and nonmetastatic nodes and the critical lymph node size after neoadjuvant chemoradiation therapy.

METHODS

The 201 lymph nodes available from 31 patients with ypT0-2 rectal cancer were reviewed and measured. Lymph nodes were compared according to the presence of metastases and size.

RESULTS

There was a mean of 6.5 lymph nodes per patient and 12 positive nodes of the 201 recovered (6%). Ninety-five percent of all lymph nodes were <5 mm, whereas 50% of positive lymph nodes were <3 mm. Metastatic lymph nodes were significantly greater in size (5.0 vs. 2.5mm; P = 0.02). Lymph nodes >4.5 mm had a greater risk of harboring metastases (P = 0.009).

CONCLUSIONS

Patients with ypT0-2 rectal cancer following neoadjuvant chemoradiation have very small perirectal nodes. Individual metastatic lymph nodes are significantly larger. However, a significant number of lymph nodes after neoadjuvant chemoradiation (negative and positive) are <3 mm. Individual lymph node size is not a good predictor of nodal metastases and may lead to inaccurate radiologic staging.

The role of carcinoembriogenic antigen in predicting response and survival to neoadjuvant chemoradiotherapy for distal rectal cancer

PURPOSE

Carcinoembriogenic antigen (CEA) is the most frequently used tumor marker in rectal cancer. A decrease in carcinoembriogenic antigen after radical surgery is associated with survival in these patients. Neoadjuvant chemoradiotherapy may lead to significant primary tumor downstaging, including complete tumor regression in selected patients. Therefore, we hypothesized that a decrease in CEA after neoadjuvant chemoradiotherapy could reflect tumor response to chemoradiotherapy, affecting final disease stage and ultimately survival.

METHODS

Patients with distal rectal cancer managed by neoadjuvant chemoradiotherapy and available pretreatment and postchemoradiotherapy levels of CEA were eligible for the study. Outcomes studied included final disease stage, relapse, and survival, and these were compared according to initial CEA level, post-chemoradiotherapy CEA level, and the reduction in CEA.

RESULTS

Overall 170 patients were included. Post-chemoradiotherapy CEA levels <5 ng/ml were associated with increased rates of complete clinical response and pathologic response. Additionally, postchemoradiotherapy CEA levels <5 ng/ml were associated with increased overall and disease-free survival (P = 0.01 and P = 0.03). There was no correlation between initial CEA level or reduction in CEA and complete response or survival.

CONCLUSION

A postchemoradiotherapy CEA level <5 ng/ml is a favorable prognostic factor for rectal cancer and is associated with increased rates of earlier disease staging and complete tumor regression. Postchemoradiotherapy CEA levels may be useful in decision making for patients who may be candidates for alterative treatment strategies.

Absence of lymph nodes in the resected specimen after radical surgery for distal rectal cancer and neoadjuvant chemoradiation therapy: what does it mean?

PURPOSE

The number of retrieved lymph nodes during radical surgery has been considered of great importance to ensure adequate staging and radical resection. However, this finding may not be applicable after neoadjuvant therapy in which, not only is there a decrease in lymph nodes recovered, but also a subgroup of patients with absence of lymph nodes in the resected specimen.

METHODS

Patients with absence of lymph nodes were compared with patients with ypN0 disease and patients with ypN+ disease.

RESULTS

Thirty-two patients (11 percent) had absence of lymph nodes, 171 patients (61 percent) had ypN0 disease, and 78 patients (28 percent) had ypN+ disease. Patients with absence of lymph nodes had significantly lower ypT status (ypT0-1, 40 vs. 13 percent; P<0.001) and decreased risk of perineural invasion (6 vs. 21 percent; P=0.04) compared with ypN0 patients. Five-year disease-free survival (74 percent) was similar to patients with ypN0 (59 percent; P=0.2), and both were significantly better than patients with ypN+ disease (30 percent; P<0.001).

CONCLUSIONS

Absence of lymph nodes retrieved from the resected specimen is associated with favorable pathologic features (ypT and perineural invasion status) and good disease-free survival rates. In this setting, absence of retrieved lymph nodes may reflect improved response to neoadjuvant chemoradiation therapy rather than inappropriate or suboptimal oncologic radicality.

Instalação e resultados preliminares de programa de rastreamento populacional de câncer colorretal em município brasileiro

RACIONAL: O câncer colorretal é causa de morte de cerca de 500.000 pessoas-ano em todo o mundo, sendo a terceira principal causa de óbito por neoplasia. A mortalidade destes pacientes está diretamente relacionada com o estádio em que é feito o diagnóstico. O rastreamento leva ao diagnóstico precoce, sendo uma forma eficaz de diminuir a mortalidade. OBJETIVO: Estimar qual o efeito de uma campanha de prevenção do câncer colorretal em um município brasileiro, estimar a incidência da doença e antever redução da incidência de CCR a longo prazo. MÉTODOS: O rastreamento consistiu de em realizar o teste de sangue oculto do tipo imunológico (Hemosure®), em toda população acima de 40 anos que estivesse assintomática e que nunca tivesse sido rastreada para câncer colorretal. As pessoas que apresentassem resultado negativo eram cadastradas para exame de controle anual. Já os com positivo eram encaminhados à colonoscopia para avaliar a presença de lesões neoplásicas ou pré-neoplásicas e se presentes seguiam para tratamento. Todos os pacientes deveriam ser seguidos por período de pelo menos 10 anos. Durante quatro dias esteve exposto no Ginásio Desportivo Municipal, o "Intestino Gigante" - réplica do cólon humano criado pela ABRAPRECI - informando de forma clara e expositiva à população quais as principais partes e doenças deste órgão, através de alto-falantes embutidos na sua estrutura. O Hemosure® foi o teste de sangue oculto empregado. Pacientes que apresentaram resultados com necessidade de intervenção cirúrgica ou outro tipo de tratamento eram referenciados para centros especializados próximos RESULTADOS: No período de agosto de 2006 a março de 2007 foram entregues 4.567 Hemosure® para pessoas que atendiam os critérios de inclusão. Esse número correspondeu a 54,8% da população acima de 40 anos do município. Do total, 905 (19,8%) não foram devolvidos e 22 (0,5%) não puderam ser analisados. Desta forma, 3.640 exames foram analisados, o que corresponde a 43,7% da população alvo e 79,7% dos exames distribuídos. Foram obtidos 390 exames com resultado positivo (10,7%) e 3.250 negativos (89,3%). Dos 245 pacientes positivos convocados a realizar colonoscopia, 33 (13,5%) se recusaram. Das 212 colonoscopias realizadas foram diagnosticados: 53 pacientes com doença diverticular, 59 com 1 ou mais pólipos, 9 com adenocarcinomas e 91 colonoscopias normais. Os pacientes com adenocarcinoma, 3 foram tratados endoscopicamente por portarem lesão pequena e precoce, os outros 6 pacientes foram encaminhados para tratamento cirúrgico e quimioterápico. CONCLUSÕES: Os resultados preliminares são insuficientes para estimar qual foi o real efeito da campanha, contudo, pode-se antever redução da incidência de CCR a longo prazo, além de antecipação do diagnóstico e, portanto, do estádio da doença melhorando o prognóstico.

Interval between surgery and neoadjuvant chemoradiation therapy for distal rectal cancer: does delayed surgery have an impact on outcome?

BACKGROUND

The optimal interval between neoadjuvant chemoradiation therapy (CRT) and surgery in the treatment of patients with distal rectal cancer is controversial. The purpose of this study is to evaluate whether this interval has an impact on survival.

METHODS AND MATERIALS

Patients who underwent surgery after CRT were retrospectively reviewed. Patients with a sustained complete clinical response (cCR) 1 year after CRT were excluded from this study. Clinical and pathologic characteristics and overall and disease-free survival were compared between patients undergoing surgery 12 weeks or less from CRT and patients undergoing surgery longer than 12 weeks from CRT completion and between patients with a surgery delay caused by a suspected cCR and those with a delay for other reasons.

RESULTS

Two hundred fifty patients underwent surgery, and 48.4% had CRT-to-surgery intervals of 12 weeks or less. There were no statistical differences in overall survival (86% vs. 81.6%) or disease-free survival rates (56.5% and 58.9%) between patients according to interval (< or =12 vs. >12 weeks). Patients with intervals of 12 weeks or less had significantly higher rates of Stage III disease (34% vs. 20%; p = 0.009). The delay in surgery was caused by a suspected cCR in 23 patients (interval, 48 +/- 10.3 weeks). Five-year overall and disease-free survival rates for this subset were 84.9% and 51.6%, not significantly different compared with the remaining group (84%; p = 0.96 and 57.8%; p = 0.76, respectively).

CONCLUSIONS

Delay in surgery for the evaluation of tumor response after neoadjuvant CRT is safe and does not negatively affect survival. These results support the hypothesis that shorter intervals may interrupt ongoing tumor necrosis.

Peritumoral inflammatory infiltrate is not a prognostic factor in distal rectal cancer following neoadjuvant chemoradiation therapy

BACKGROUND

Peritumoral inflammatory response has been considered a good prognostic factor for colorectal cancer. However, this has not been evaluated in patients submitted to neoadjuvant therapy for distal rectal cancer. For this reason, we decided to study the effect of the presence of this pathological finding on disease recurrence and survival.

METHODS

The peritumoral inflammatory infiltrate from recovered pathological specimens of patients operated after neoadjuvant therapy for distal rectal cancer was graded (positive or negative). Patients were compared according to the presence of peritumoral inflammatory response.

RESULTS

Of the 168 patients, 63 (37%) patients had a peritumoral inflammatory response. The lack of peritumoral inflammatory response was significantly associated with the presence of mucinous component (13 vs 3%; p = 0.02). Five-year overall survival (91 vs 81%) and disease-free survival (57 vs 48%) were not significantly different between patients with and without peritumoral inflammatory response (p = 0.5 and 0.3, respectively).

CONCLUSIONS

Peritumoral inflammatory response is not a favorable prognostic factor in patients with distal rectal cancer after neoadjuvant chemoradiation therapy. Possibly, the immunosuppressive action of chemoradiation therapy may lead to a loss of function of the immunological response, which may represent a disadvantage of the neoadjuvant approach for the management of distal rectal cancer.

Local excision for ypT2 rectal cancer--much ado about something

BACKGROUND

The role of local excision for pT2 distal rectal cancer has been challenged because of the observation of high rates of lymph node metastases and local failure. However, neoadjuvant chemoradiation therapy (CRT) has led to increased local disease control and significant tumor downstaging, possibly decreasing rates of lymph node metastases. In this setting, a possible role for local excision of ypT2 has been suggested.

METHODS

A total of 401 patients with distal rectal cancer underwent neoadjuvant CRT. Tumor response assessment was performed after at least 8 weeks from CRT completion. One hundred and twelve patients with complete clinical response were not immediately operated on and were excluded from the study, and 289 patients with incomplete clinical response were managed by radical surgery. Patients with final pathological stage ypT2 were analyzed to determine the risk of unfavorable pathological features that could represent unacceptable risk for local failure after local excision.

RESULTS

Eighty-eight (30%) patients had ypT2 rectal cancer. Final ypT status was not associated with pretreatment radiological staging (p = 0.62). ypT status was significantly associated with the risk of lymph node metastases, risk of perineural and vascular invasion, and recurrence (p = 0.001). Lymph node metastases were present in 19% of patients with ypT2 rectal cancer. The risk of lymph node metastases in ypT2 was associated with the presence of perineural invasion (47% vs 4%; p = <0.001), vascular invasion (59% vs 6%; p < 0.001), and decreased mean interval CRT surgery (12 vs 18 weeks; p < 0.001), but not with mean tumor size (3.2 vs 3.1 cm; p = 0.8). Disease-free and overall survival rates were significantly better for patients with ypT2N0 (p = 0.02 and 0.006, respectively). Fifty-five (63%) patients with ypT2 had at least one unfavorable pathological feature for local excision (lymph node metastases, vascular or perineural invasion, mucinous type or tumor size >3 cm).

CONCLUSION

Lymph node metastases were present in 19% of patients with ypT2 and were significantly associated with poor overall and disease-free survival rates. The risk of lymph node metastases could not be predicted by radiological staging or tumor size. Radical surgery should be considered the standard treatment option for ypT2 rectal cancer after CRT.

Trends in tumor location in gastric carcinoma over a 28-year period

BACKGROUND/AIMS

Gastric cancer is still a leading cause of cancer death in the world and in Brazil. Historically a majority of gastric tumors were located in the distal third of the stomach. However, several studies have shown a shift in tumor location towards the proximal third.

METHODOLOGY

Japanese rules for gastric cancer treatment were followed. All patients that were submitted to surgical resection for gastric cancer between 1971 and 1998 were included. These patients were divided into 3 time periods and classifled according to tumor location.

RESULTS

1021 patients underwent gastric resection for adenocarcinoma. The distal third of the stomach (53.7%) was the most common site. The proportion of tumors located in the proximal and middle thirds of the stomach increased significantly from 8.1% to 15% and 16.2 to 29.8% respectively at the last decade.

CONCLUSIONS

The findings of this study suggest an increase in the incidence of tumors to the proximal third of the stomach. However the high incidence of these tumors reported in literature is not confirmed.

Endoscopic management of postoperative stapled colorectal anastomosis hemorrhage

Rectal bleeding following colorectal anastomosis is common but usually self-limited. Continuous hemorrhage is rare, and when it occurs, often requires further treatment. The most frequently used strategies for treatment of stapled anastomotic hemorrhage are clinical observation with or without blood transfusion, rectal packing, angiographic identification of the bleeding site with vasopressin infusion or embolization, and endoscopic eletrocoagulation. We report the case of a 49-year-old man with uncomplicated diverticular disease who was treated by laparoscopic sigmoidectomy, with double-stapled colorectal anastomosis. Six hours later, the patient presented intense rectal bleeding and was taken to the operation room for urgent colonoscopic examination. After complete removal of blood clots inside the rectum, a bleed localized at the anastomotic site was identified and submucosal peri-anastomotic injection of 10 ml adrenaline (1:200 000) in saline was performed with immediate bleeding control.

Patterns of failure and survival for nonoperative treatment of stage c0 distal rectal cancer following neoadjuvant chemoradiation therapy

Neoadjuvant chemoradiation therapy (CRT) is the preferred treatment option for distal rectal cancer. Complete pathological response after CRT has led to the proposal of nonoperative approach as an alternative treatment for highly selected patients with complete clinical response. However, patterns of failure following this strategy remains undetermined. Three hundred sixty-one patients with distal rectal cancer were managed by neoadjuvant CRT including 5-FU, leucovorin, and 5040 cGy. Tumor response assessment was performed at 8 weeks following CRT. Patients with complete clinical response were not immediately operated on and were closely followed. One hundred twenty-two patients were considered to have complete clinical response after the first tumor response assessment. Of these, only 99 patients sustained complete clinical response for at least 12 months and were considered stage c0 (27.4%) and managed nonoperatively. Mean follow-up was 59.9 months. There were 13 (13.1%) recurrences: 5 (5%) endorectal, 7 (7.1%) systemic, and 1 (1%) combined recurrence. All 5 isolated endorectal recurrences were salvaged. Mean recurrence interval was 52 months for local failure and 29.5 months for systemic failure. There were five cancer-related deaths after systemic recurrences. Overall and disease-free 5-year survivals were 93% and 85%. Even though surgery remains the standard treatment for rectal cancer, nonoperative treatment after complete clinical response following neoadjuvant CRT may be safe and associated with good survival rates in a highly selected group of patients. Survival in these patients is significantly affected by systemic failure. Exclusive local failure occurs late after CRT completion and is frequently amenable to salvage therapy.

Patterns of failure and survival for nonoperative treatment of stage c0 distal rectal cancer following neoadjuvant chemoradiation therapy

Neoadjuvant chemoradiation therapy (CRT) is the preferred treatment option for distal rectal cancer. Complete pathological response after CRT has led to the proposal of nonoperative approach as an alternative treatment for highly selected patients with complete clinical response. However, patterns of failure following this strategy remains undetermined. Three hundred sixty-one patients with distal rectal cancer were managed by neoadjuvant CRT including 5-FU, leucovorin, and 5040 cGy. Tumor response assessment was performed at 8 weeks following CRT. Patients with complete clinical response were not immediately operated on and were closely followed. One hundred twenty-two patients were considered to have complete clinical response after the first tumor response assessment. Of these, only 99 patients sustained complete clinical response for at least 12 months and were considered stage c0 (27.4%) and managed nonoperatively. Mean follow-up was 59.9 months. There were 13 (13.1%) recurrences: 5 (5%) endorectal, 7 (7.1%) systemic, and 1 (1%) combined recurrence. All 5 isolated endorectal recurrences were salvaged. Mean recurrence interval was 52 months for local failure and 29.5 months for systemic failure. There were five cancer-related deaths after systemic recurrences. Overall and disease-free 5-year survivals were 93% and 85%. Even though surgery remains the standard treatment for rectal cancer, nonoperative treatment after complete clinical response following neoadjuvant CRT may be safe and associated with good survival rates in a highly selected group of patients. Survival in these patients is significantly affected by systemic failure. Exclusive local failure occurs late after CRT completion and is frequently amenable to salvage therapy.

Loop ileostomy morbidity: timing of closure matters

PURPOSE

Diverting stomas are commonly performed during ileoanal and coloanal anastomoses. We studied a series of patients after loop ileostomy closure to determine risk factors and the impact of the interval from primary operation on morbidity.

METHODS

Ninety-three consecutive patients undergoing loop ileostomy closure at a single institution after coloanal or ileoanal anastomosis were retrospectively reviewed. Complications were classified as medical or surgical according to its treatment requirements. Results were correlated to clinical and operative features.

RESULTS

Of the 93 patients, 43 were male and 50 were female with mean age of 56 years. Overall, complication rate was 17.2 percent. The most common complication was small-bowel obstruction. Complications required operative management in 3.2 percent and medical management alone in 14 percent. There was no mortality. There was no correlation between complication occurrence and age, gender, type of suture (manual or mechanical), and operative time. Complications were significantly associated with primary disease and shorter interval between primary operation and ileostomy closure. Regarding the optimal interval between primary surgery and ileostomy closure, the cutoff value for increased risk of developing postoperative complications was 8.5 weeks, below which the risk of such occurrence was significantly higher with a sensitivity rate of 88 percent.

CONCLUSIONS

Diverting loop ileostomy adds little cumulative morbidity to the primary operation and is a safe option for diversion to protect a low colorectal anastomosis. To further reduce morbidity, the interval between primary operation and ileostomy closure should be no shorter than 8.5 weeks.

Laparoscopic versus standard appendectomy outcomes and cost comparisons in the private sector

Minimally invasive surgery has been proposed as the preferred treatment strategy for various gastrointestinal disorders due to shorter hospital stay, less pain, quicker return to normal activities, and improved cosmesis. However, these advantages may not be straightforward for laparoscopic appendectomy, and optimal management of remains controversial. One hundred forty-eight patients with clinical and radiologic diagnoses of acute appendicitis treated in two different hospitals were retrospectively reviewed. Seventy-eight patients underwent laparoscopic appendectomy in hospital A and 70 patients underwent standard appendectomy in hospital B. Patients treated by either type of surgery were compared in terms of clinical and pathologic features, operation characteristics, complications, and costs. There were no significant differences between both groups in terms of clinical features, radiologic studies, complications, and final pathology findings (P > .05). Hospital stay was significantly shorter and bowel movements recovered quicker in the laparoscopy group. However, overall and operating room costs were significantly higher in patients treated by laparoscopy (P < .01). Our series show a subtle difference in terms of hospital stay and bowel movement recovery, favoring patients treated by laparoscopy. However, these results have to be carefully examined and weighed, because overall costs and operating room costs were significantly higher in the laparoscopy group.