Current trends in gas-synergized phototherapy for improved antitumor theranostics

Phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), has been considered an elegant solution to eradicate tumors due to its minimal invasiveness and low systemic toxicity. Nevertheless, it is still challenging for phototherapy to achieve ideal outcomes and clinical translation due to its inherent drawbacks. Owing to the unique biological functions, diverse gases have attracted growing attention in combining with phototherapy to achieve super-additive therapeutic effects. Specifically, gases such as nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) have been proven to kill tumor cells by inducing mitochondrial damage in synergy with phototherapy. Additionally, several gases not only enhance the thermal damage in PTT and the reactive oxygen species (ROS) production in PDT but also improve the tumor accumulation of photoactive agents. The inflammatory responses triggered by hyperthermia in PTT are also suppressed by the combination of gases. Herein, we comprehensively review the latest studies on gas-synergized phototherapy for cancer therapy, including (1) synergistic mechanisms of combining gases with phototherapy; (2) design of nanoplatforms for gas-synergized phototherapy; (3) multimodal therapy based on gas-synergized phototherapy; (4) imaging-guided gas-synergized phototherapy. Finally, the current challenges and future opportunities of gas-synergized phototherapy for tumor treatment are discussed. STATEMENT OF SIGNIFICANCE: 1. The novelty and significance of the work with respect to the existing literature. (1) Strategies to design nanoplatforms for gas-synergized anti-tumor phototherapy have been summarized for the first time. Meanwhile, the integration of various imaging technologies and therapy modalities which endow these nanoplatforms with advanced theranostic capabilities has been summarized. (2) The mechanisms by which gases synergize with phototherapy to eradicate tumors are innovatively and comprehensively summarized. 2. The scientific impact and interest. This review elaborates current trends in gas-synergized anti-tumor phototherapy, with special emphases on synergistic anti-tumor mechanisms and rational design of therapeutic nanoplatforms to achieve this synergistic therapy. It aims to provide valuable guidance for researchers in this field.

Chemotherapy for patients with unresectable or metastatic small bowel adenocarcinoma: a systematic review

BACKGROUND

There is no standard chemotherapy available for unresectable or metastatic small bowel adenocarcinoma (SBA) because of its rarity. This systematic review aims to assess the efficacy and safety of chemotherapy for patients with unresectable or metastatic SBA.

METHODS

In accordance with the PRISMA statements, literature search was conducted using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. The included studies were prospective randomized, nonrandomized, or observational studies. Risk of bias was assessed the ROBINS-I tool.

RESULTS

Seven prospective single-arm Phase II studies were included in this review. Six of them were assessed as having a moderate risk of bias and one as having a serious risk of bias. A meta-analysis was not performed, because the studies were single-arm. Systemic chemotherapy based on fluoropyrimidine regimens achieved favorable outcomes with acceptable adverse effects as a first therapy; however, the regimens differed in each study. The object response rate was 18-50%, and the disease control rate was 29-87%. With 5-fluorouracil, adriamycin, and mitomycin-C regimen, one treatment-related death occurred. A second line of therapy including chemotherapy with nab-paclitaxel also showed favorable efficacy. The object response rate was 20%, and the disease control rate was 50%.

CONCLUSIONS

Systemic chemotherapy based on fluoropyrimidine regimens was mainly used for unresectable or metastatic SBA. While it may achieve favorable outcomes with acceptable adverse effects, further evidence is needed.