PEGylated chitosan-coated nanophotosensitizers for effective cancer treatment by photothermal-photodynamic therapy combined with glutathione depletion.

The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a promising strategy for cancer treatment. However, the poor photostability and photothermal conversion efficiency (PCE) of organic small-molecule photosensitizers, and the intracellular glutathione (GSH)-mediated singlet oxygen scavenging largely decline the antitumor efficacy of PTT and PDT. Herein, a versatile nanophotosensitizer (NPS) system is developed by ingenious incorporation of indocyanine green (ICG) into the PEGylated chitosan (PEG-CS)-coated polydopamine (PDA) nanoparticles via multiple π-π stacking, hydrophobic and electrostatic interactions. The PEG-CS-covered NPS showed prominent colloidal and photothermal stability as well as high PCE (ca 62.8 %). Meanwhile, the Michael addition between NPS and GSH can consume GSH, thus reducing the GSH-induced singlet oxygen scavenging. After being internalized by CT26 cells, the NPS under near-infrared laser irradiation produced massive singlet oxygen with the aid of thermo-enhanced intracellular GSH depletion to elicit mitochondrial damage and lipid peroxide formation, thus leading to ferroptosis and apoptosis. Importantly, the combined PTT and PDT delivered by NPS effectively inhibited CT26 tumor growth in vivo by light-activated intense hyperthermia and redox homeostasis disturbance. Overall, this work presents a new tactic of boosting antitumor potency of ICG-mediated phototherapy by PEG-CS-covered NPS.

The role of adjuvant chemotherapy in stage II colorectal cancer patients.

PURPOSE: Adjuvant chemotherapy use in stage II colorectal cancer (CRC) is debated. We evaluated the prognostic significance of clinicopathological features recommended by most guidelines for identifying high-risk stage II CRC and adjuvant chemotherapeutic response. METHODS: We enrolled 1,039 stage II CRC patients who underwent curative surgery at Taipei Veterans General Hospital from January 2005 to December 2010. Seventy-seven patients who received radiotherapy were excluded. The endpoint was disease-free survival. RESULTS: Of 962 patients, 37 had stage T4 tumors; 50, lymphovascular invasion; 39, poor differentiation; 249, preoperative carcinoembryonic antigen (CEA) levels >5 ng/mL; and 53 underwent emergent operations. One hundred ninety-four patients received 5-fluorouracil-based adjuvant chemotherapy. During a median follow-up period of 60.2 months, recurrence developed in 110 patients (11.4 %). The 5-year disease-free survival (DFS) was 87.6 %. In multivariate analysis, preoperative CEA >5 ng/ml (p = 0.001), emergent operation for obstruction/perforation (p = 0.008), lymphovascular invasion (p = 0.014), and T4 disease (p = 0.030) were significantly associated with poor DFS. High-risk stage II patients (n = 484) benefited from adjuvant chemotherapy (5-year DFS with and without adjuvant chemotherapy, 87.3 vs. 78.9 %; p = 0.028). CONCLUSIONS: Adjuvant chemotherapy improved DFS in high-risk stage II CRC patients, but not in low-risk patients.

Assessment of the value of carcinoembryonic antigen reduction ratio as a prognosis factor in rectal cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) is the most widely used tumor marker for colorectal cancer. This study aimed to investigate the role of CEA reduction ratio after preoperative chemoradiotherapy (CRT). METHODS: We enrolled 284 patients who underwent preoperative CRT followed by radical surgical resection. Patients were divided into 3 groups: serum CEA levels before CRT (pre-CRT CEA) less than 5 ng/mL (group 1); pre-CRT CEA of 5 ng/mL or more with CEA reduction ratio of 50% or more (group 2); and pre-CRT CEA of 5 ng/mL or more with CEA reduction ratio less than 50% (group 3). RESULTS: The 5-year disease-free survival (DFS) rate was not different between groups 1 (71.8%) and 2 (69.4%) but was significantly lower in group 3 (49.5%). CEA group, lymph node status after CRT (ypN) stage, and histologic type were independent prognostic factors for DFS on multivariate analysis. CONCLUSIONS: CEA reduction ratio might be an independent prognostic factor for DFS in rectal cancer patients treated with preoperative CRT and radical surgery.

Celecoxib plus chemoradiotherapy for locally advanced rectal cancer: a phase II TCOG study.

BACKGROUND: To report the results of a phase II trial combining celecoxib and preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. PATIENTS AND METHODS: Patients with clinical stage II or III rectal cancer were treated with radiotherapy of 44 Gy in 22 fractions. Concurrent chemotherapy consisted of oral tegafur-uracil and folinate on days 1-30 and 38-65. Celecoxib (400 mg/day) given from days 1 to 65. Surgery was done on day 70. The expression of cyclooxygenase 2 (COX-2) in tumor tissues was evaluated microscopically as a prognostic factor. RESULTS: From 2008 to 2011, 53 patients completed CRT+ celecoxib therapy and 47 received radical surgery. Grade 3 diarrhea developed in 5 (9%). Grade 4 anemia was seen in 2 (4%). Pathological complete response (pCR) was seen in 6 (13%). T or N downstaging found in 38 (81%). Sphincter preservation was achieved in 77% of low-positioned tumors. Patients with tumors expressing high-level COX-2 after CRT + celecoxib treatment had inferior pelvic control (P = 0.01), disease-free survival (P = 0.04), and overall survival (P = 0.03) than those with low-level expression. CONCLUSIONS: Celecoxib can be safely combined with preoperative CRT for rectal cancer. More intensified adjuvant therapy may be considered for tumors expressing high-level COX-2 after CRT and surgery.

Concurrent chemoradiotherapy followed by metastasectomy converts to survival benefit in stage IV rectum cancer.

BACKGROUND: To investigate the impact of concurrent chemoradiotherapy (CCRT) on stage IV rectum cancer. METHODS: Between 2000 and 2011, 297 consecutive patients diagnosed with stage IV rectum cancer (synchronous metastasis) were enrolled. Cox proportional hazard analyses were used for prognostic factors determination, and the Kaplan-Meier method was used for survival analyses. Propensity scores with the one-to-one nearest-neighbor matching model were used to select matched patients for validation studies. RESULTS: In total, 63 patients received CCRT and 234 did not. The patients in the CCRT group were younger, had more low-lying lesions, and had more T4 lesions, lung metastases, metastasectomies, and oxaliplatin-based upfront chemotherapy. Before propensity-score matching, a younger age (HR = 0.662, P = 0.016), lower carcinoembryonic antigen (CEA) level (≤20 ng/ml) (HR = 0.531, P = 0.001), no metastasectomy (HR = 3.214, P < 0.001), and no CCRT (HR = 1.844, P = 0.019) were independent prognostic factors after controlling for other confounding factors. After matching, only CEA and metastasectomy, but not CCRT, were independent prognostic factors. The survival benefit of CCRT was restricted to patients who undergo subsequent metastasectomy. CONCLUSIONS: Upfront CCRT only provided a survival benefit in patients with stage IV rectum cancer who undergo subsequent metastasectomy.

Adjuvant oxaliplatin- or irinotecan-containing chemotherapy improves overall survival following resection of metachronous colorectal liver metastases.

PURPOSE: Adjuvant systemic 5-fluorouracil (5-FU)-based chemotherapy improves survival after resection of synchronous colorectal liver metastases (CLMs), but not metachronous. We retrospectively examined if adjuvant chemotherapy with new regimen containing oxaliplatin or irinotecan improved survivals after resection of metachronous CLMs. METHODS: Between 2000 and 2007, 52 patients having undertaken resection of metachronous CLMs with curative intent were identified from Taipei Veterans General Hospital hospitalization registry. One patient with perioperative mortality and another being lost to follow-up within 3 months after metastasectomy were excluded. Thirty-one patients experienced six to 12 cycles of FOLFOX or FOLFIRI chemotherapy while 19 patients with 5-FU/leucovorin (LV)-based chemotherapy following CLM resection. The primary end point was disease-free survival (DFS) and secondary end point, overall survival (OS). RESULTS: By the univariate analysis, median DFS was 34.3 months in the FOLFOX/FOLFIRI group vs 14.2 months in the 5-FU/LV group (P = 0.022). The median OS and 5-year survival rates were longer than 57.7 months (not reached, with median follow-up of 35.5 months) and 54.0%, respectively, in the FOLFOX/FOLFIRI group compared to 49 months and 34.6% in the 5-FU/LV group (P = 0.027). FOLFOX/FOLFIRI chemotherapy was shown by multivariate analyses to be an independent factor predicting a better DFS (hazard ratio [HR] = 0.37; 95% CI: 0.15-0.94; P = 0.036) and a better OS (HR = 0.27; 95% CI: 0.083-0.86, P = 0.026) than 5-FU/LV-based. CONCLUSIONS: Adjuvant FOLFOX/FOLFIRI chemotherapy following resection of metachronous CLMs is demonstrated to have better DFS and OS than 5-FU/LV chemotherapy.