Metronomic Therapy in Oral Squamous Cell Carcinoma

Combined Metronomic Chemo-immunotherapy (CMCI) in Head and Neck Cancers-An Experience from a Developing Country

Head and neck squamous cell carcinomas (HNSCC) have proven to be inherently resistant to systemic treatments as a result of histological, molecular, and etiological heterogeneity, with limited responses seen after second-line therapy and beyond. With limited treatment options after progression on systemic chemotherapy in HNSCCs, immunotherapy has a role to play with improved results. In this prospective, observational, non-randomized, open-label study, a total of 12 patients with advanced, relapsed, or metastatic HNSCC received Inj. Nivolumab weight-based dose of 3 mg per kg, intravenously every 2 weeks along with low-dose capecitabine 500 mg twice a day, was prospectively assessed. The patient's clinical, hematological, and staging characteristics were described and the clinical benefit rate (CBR) was calculated. A total of 12 patients received the combined metronomic chemo-immunotherapy (CMCI). The majority of patients were belonging to ECOG-PS 1(66%), with all patients being in stage IV disease. Six, four, and two patients received immunotherapy as the 5th, 3rd, and 4th line of therapy, respectively. Nivolumab and low-dose capecitabine were used in all 12 patients. CBR was seen in 66% (8/12) of patients, one patient died due to hepatitis and hepatic encephalopathy, another patient died due to pneumonia and respiratory complications, two patients had progressive disease, and two patients with stable disease discontinued treatment because of financial constraints and kept on capecitabine alone. The majority tolerated therapy well with no grade 3/4 immune-related adverse events (IRAEs). Two patients required supportive therapy with packed red cell transfusion and albumin infusions. Six-month overall survival (OS) and progression-free survival (PFS) in the study population were 83.3% and 66.6%, respectively. In conclusion, nivolumab along with metronomic chemotherapy with low-dose capecitabine was very well tolerated and exhibited anti-tumor activity with a CBR of 66%, 6-month OS of 83.3%, and 6-month PFS of 66.6%, in extensively pretreated patients with HNSCCs. Additional studies of nivolumab and metronomic chemotherapy and immuno-immuno combination therapy in these diseases are ongoing.

Macrophage membrane-camouflaged pH-sensitive nanoparticles for targeted therapy of oral squamous cell carcinoma

BACKGROUND

Oral cancer is the most common malignant tumor of the head and neck, and 90% of cases are oral squamous cell carcinoma (OSCC). Chemotherapy is an important component of comprehensive treatment for OSCC. However, the clinical treatment effect of chemotherapy drugs, such as doxorubicin (DOX), is limited due to the lack of tumor targeting and rapid clearance by the immune system. Thus, based on the tumor-targeting and immune evasion abilities of macrophages, macrophage membrane-encapsulated poly(methyl vinyl ether alt maleic anhydride)-phenylboronic acid-doxorubicin nanoparticles (MM@PMVEMA-PBA-DOX NPs), briefly as MM@DOX NPs, were designed to target OSCC. The boronate ester bonds between PBA and DOX responded to the low pH value in the tumor microenvironment, selectively releasing the loaded DOX.

RESULTS

The results showed that MM@DOX NPs exhibited uniform particle size and typical core-shell structure. As the pH decreased from 7.4 to 5.5, drug release increased from 14 to 21%. The in vitro targeting ability, immune evasion ability, and cytotoxicity of MM@DOX NPs were verified in HN6 and SCC15 cell lines. Compared to free DOX, flow cytometry and fluorescence images demonstrated higher uptake of MM@DOX NPs by tumor cells and lower uptake by macrophages. Cell toxicity and live/dead staining experiments showed that MM@DOX NPs exhibited stronger in vitro antitumor effects than free DOX. The targeting and therapeutic effects were further confirmed in vivo. Based on in vivo biodistribution of the nanoparticles, the accumulation of MM@DOX NPs at the tumor site was increased. The pharmacokinetic results demonstrated a longer half-life of 9.26 h for MM@DOX NPs compared to 1.94 h for free DOX. Moreover, MM@DOX NPs exhibited stronger tumor suppression effects in HN6 tumor-bearing mice and good biocompatibility.

CONCLUSIONS

Therefore, MM@DOX NPs is a safe and efficient therapeutic platform for OSCC.

Whole exome sequencing uncovers HRAS mutations as potential mediators of resistance to metronomic chemotherapy

OBJECTIVES

The aim of this pilot study is to identify the genetic factors that contribute to the response of metronomic chemotherapy in head and neck squamous cell carcinoma (HNSCC) patients using whole-exome sequencing (WES). This study would facilitate the identification of predictive biomarkers, which would enable personalized treatment strategies and improve treatment outcomes for patients with HNSCC.

MATERIALS AND METHODS

We have selected patients with recurrent head and neck cancer who underwent metronomic chemotherapy. Sequential tumor biopsies were collected from the patients at different stages of treatment to capture the genomic alterations and tumor evolution during metronomic chemotherapy and sequenced using WES.

RESULTS

We identified several known HNSCC hallmark genes reported in COSMIC, including KMT2B, NOTCH1, FAT1, TP53, HRAS, CASP8, and CDKN2A. Copy number alteration analysis revealed amplifications and deletions in several oncogenic and tumor suppressor genes. COSMIC Mutational Signature 15 associated with defective DNA mismatch repair was enriched in 73% of HNSCC samples. Further, the comparison of genomic alterations between responders and non-responders identified HRAS gene uniquely mutated in non-responders that could potentially contribute to resistance against metronomic chemotherapy.

DISCUSSION

Our findings corroborate the molecular heterogeneity of recurrent HNSCC tumors and establish an association between HRAS mutations and resistance to metronomic chemotherapy, suggesting HRAS as a potential therapeutic target. Combining HRAS inhibitors with metronomic regimens could improve treatment sensitivity in HRAS-mutated HNSCC patients. Further studies are needed to fully elucidate the genomic mechanisms underlying the response to metronomic chemotherapy.

Metronomic Chemotherapy in Oral Cancer: A Review

Treatment of locally advanced oral cancer requires multidisciplinary care, including surgery, radiotherapy, and chemotherapy, which varies based on the stage of the disease, site of involvement, and surgical access. Oral cancer usually presents with an increased recurrence rate and potential for distant metastatic spread. It confers a poor prognosis with a 50% mortality rate after five years. Oral metronomic chemotherapy aims to achieve higher patient compliance due to its ease of administration, lower dosage, and lesser side effects than conventional IV regimens of platinum-based drugs. In this review, we have summarized the relevant literature to benefit the readers regarding the potential application of metronomic therapy in the management of oral cancer.

EphA4 signaling is involved in the phenotype of well-differentiated oral squamous cell arcinoma with decreased tumor immunity

Metronomic chemotherapy is defined as a high-frequency low-dose schedule of chemotherapy drug administration. Although metronomic chemotherapy is widely used, the mechanisms underlying resistance to metronomic chemotherapy remain unclear. Therefore, we herein conducted a single institutional phase I/II trial to assess the efficacy and safety of metronomic chemotherapy with bleomycin plus S-1, an oral 5-FU prodrug, in the neoadjuvant setting for patients with oral squamous cell carcinoma (OSCC). The response rate of well-differentiated OSCC to metronomic chemotherapy was significantly lower. We investigated differences in molecular profiles between poorly or moderately differentiated head and neck squamous cell carcinoma (HNSCC) and well-differentiated HNSCC from patients with HNSCC TCGA data. EphA4 expression positively correlated with histological differentiation. An upstream regulator analysis correlated with EphA4 expression identified pathways associated with decreased mTORC1 signaling and T cell activation, including TCR, CD3, CD28, and CD40LG. An EphA4 blocking peptide (KYL) induced mTOR activation in well-differentiated OSCC cell lines. Plasmacytoid dendritic cell and CD8⁺ T cell numbers were higher in the microenvironment of poorly or moderately differentiated HNSCC than in that of well-differentiated HNSCC. Well-differentiated HNSCC had the characteristics of "cold tumors" (immune-excluded tumors). Moreover, KYL used with chemotherapeutic drugs synergistically increased cancer cell death. Well-differentiated OSCC is depleted of immune cells, which may be partly explained by the receptor tyrosine kinase EphA4.

Cisplatin for cancer therapy and overcoming chemoresistance

Cisplatin spearheads the anticancer chemotherapeutics in present-day use although acute toxicity is its primary impediment factor. Among a plethora of experimental medications, a drug as effective or surpassing the benefits of cisplatin has not been discovered yet. Although Oxaliplatin is considered more superior to cisplatin, the former has been better for colorectal cancer while cisplatin is widely used for treating gynaecological cancers. Carcinoma imposes a heavy toll on mortality rates worldwide despite the novel treatment strategies and detection methods that have been introduced; nanomedicine combined with precision medicine, immunotherapy, volume-regulated anion channels, and fluorodeoxyglucose-positron emission tomography. Millions of deaths occur annually from metastatic cancers which escape early detection and the concomitant diseases caused by highly toxic chemotherapy that causes organ damage. It continues due to insufficient knowledge of the debilitative mechanisms induced by cancer biology. To overcome chemoresistance and to attenuate the adverse effects of cisplatin therapy, both in vitro and in vivo models of cisplatin-treated cancers and a few multi-centred, multi-phasic, randomized clinical trials in pursuant with recent novel strategies have been tested. They include plant-based phytochemical compounds, de novo drug delivery systems, biochemical/immune pathways, 2D and 3D cell culture models using small molecule inhibitors and genetic/epigenetic mechanisms, that have contributed to further the understanding of cisplatin's role in modulating the tumour microenvironment. Cisplatin was beneficial in cancer therapy for modulating the putative cellular mechanisms; apoptosis, autophagy, cell cycle arrest and gene therapy of micro RNAs. Specific importance of drug influx, efflux, systemic circulatory toxicity, half-maximal inhibition, and the augmentation of host immunometabolism have been identified. This review offers a discourse on the recent anti-neoplastic treatment strategies to enhance cisplatin efficacy and to overcome chemoresistance, given its superiority among other tolerable chemotherapies.