Reassessment of the role of induction chemotherapy for head and neck cancer

Role of Natural Killer Cells as Cell-Based Immunotherapy in Oral Tumor Eradication and Differentiation Both In Vivo and In Vitro

Despite advancements in the field of cancer therapeutics, the five-year survival rate remains low in oral cancer patients. Therefore, the effective therapeutics are needed against oral cancer. Also, several studies including ours, have shown severely suppressed function and number of NK cells in oral cancer patients. In this review, we discuss the approach to inhibit the tumor growth and metastasis by direct killing or NK cell-mediated tumor differentiation. This review also provides an overview on supercharging NK cells using osteoclasts and probiotic bacteria, and their efficacy as cancer immunotherapeutic in humanized-BLT mice.

Supercharged NK Cell-Based Immuotherapy in Humanized Bone Marrow Liver and Thymus (Hu-BLT) Mice Model of Oral, Pancreatic, Glioblastoma, Hepatic, Melanoma and Ovarian Cancers

In this paper, we review a number of in vitro and in vivo studies regarding the efficacy of supercharged NK (sNK) cell therapy in elimination or treatment of cancer. We have performed studies using six different types of cancer models of oral, pancreatic, glioblastoma, melanoma, hepatic and ovarian cancers using hu-BLT mice. Our in vitro studies demonstrated that primary NK cells preferentially target cancer stem-like cells (CSCs)/poorly differentiated tumors whereas sNK cells target both CSCs/poorly-differentiated and well-differentiated tumors significantly higher than primary activated NK cells. Our in vivo studies in humanized-BLT mice showed that sNK cells alone or in combination with other cancer therapeutics prevented tumor growth and metastasis. In addition, sNK cells were able to increase IFN-γ secretion and cytotoxic function by the immune cells in bone marrow, spleen, gingiva, pancreas and peripheral blood. Furthermore, sNK cells were able to increase the expansion and function of CD8+ T cells both in in vitro and in vivo studies. Overall, our studies demonstrated that sNK cells alone or in combination with other cancer therapeutics were not only effective against eliminating aggressive cancers, but were also able to increase the expansion and function of CD8+ T cells to further target cancer cells, providing a successful approach to eradicate and cure cancer.

Multifocal regression and pathologic response predicts recurrence after neoadjuvant chemotherapy in head and neck squamous cell carcinoma

OBJECTIVES

Complete pathological response after neoadjuvant chemotherapy (NAC) in head and neck squamous cell carcinomas (HNSCC) is a good prognostic factor. Multifocal regression post-NAC in breast cancer has proven to impact locoregional control (LRC) but has not been evaluated in HNSCC. We evaluate the impact of multifocal regression and major pathologic response (MPR) on survival indices in HNSCC.

MATERIALS AND METHODS

Retrospective review of HNSCC patients receiving NAC followed by surgery with curative intent between March 2016 to March 2019 at MD Anderson Cancer Center. Tumor focality (uni- or multifocal), pathologic response and other pathologic data were collected. MPR was defined as ≤ 10% residual tumor. Overall survival (OS) and LRC were analyzed and multivariate Cox regression analysis was performed.

RESULTS

101 patients were analyzed, with 18.8% pathologic complete response, 18.8% with 1-10% viable tumor and 60.4% with > 10% viable tumor. 61 (60.4%) had unifocal disease while 19 (18.8%) had multifocal disease. Tumor focality was significantly associated with LRC but not OS, where the 3-year LRC was 82%, 69% and 52% (p = 0.015) for no viable tumor, unifocal disease and multifocal disease respectively. On multivariate analysis, multifocal disease (HR 10.43; 95 %CI 1.24-87.5) and extranodal extension (HR 4.4; 95 %CI 1.60-12.07) continued to be significant independent predictors of LRC. MPR group displayed significantly better 3-year OS (75% vs 51%, p = 0.041) and 3-year LRC (80% vs 62%, p = 0.011) than those with > 10% viable tumor.

CONCLUSION

Multifocal regression and less than MPR after NAC in HNSCC predicts for locoregional recurrence and should be routinely reported.

Role of cancer stem cell markers ALDH1, BCL11B, BMI-1, and CD44 in the prognosis of advanced HNSCC

Purpose

Cancer stem cells (CSCs) are held accountable for the progress of head and neck squamous cell carcinoma (HNSCC). In the presented study, the authors evaluated the prognostic value of CSC markers in two particular HNSCC cohorts.

Methods

This two cohort study consisted of 85 patients with advanced stage HNSCC, treated with primary radio(chemo)therapy (pRCT), and 95 patients with HNSCC, treated with surgery and partially adjuvant radio(chemo)therapy. Overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) were assessed. Samples were assessed for the expression of different molecular stem cell markers (ALDH1, BCL11B, BMI‑1, and CD44).

Results

In the pRCT cohort, none of the baseline patient and tumor features exhibited a statistically significant relation with survival in either the cohort or the human papillomavirus (HPV)-stratified subcohorts. High expression of BMI‑1 significantly decreased OS and DFS, while high expression of CD44 decreased all modes of survival. Multivariate analysis showed significant prognostic influence for all tested CSC markers, with high BMI‑1 and CD44 decreasing survival (BMI-1: OS, DFS, DSS; CD44: OS, DFS) and high ALDH1 and BCL11B showing a beneficial effect on survival (ALDH1: OS, DFS; BCL11B: OS, DSS). In the surgical cohort, classical prognosticators such as HPV status, R1 resection, and nodal status in HPV-negative HNSCC played a significant role, but the tested CSC markers showed no significant effect on prognosis.

Conclusion

Although validation in independent cohorts is still needed, testing for CSC markers in patients with advanced or late stage HNSCC might be beneficial, especially if many comorbidities exist or disease is irresectable. The findings might guide the development and earlier use of targeted therapies in the future.

Electronic supplementary material

The online version of this article (10.1007/s00066-020-01653-5) contains supplementary material, which is available to authorized users.

Impact of induction chemotherapy and socioeconomics on sinonasal undifferentiated carcinoma survival

BACKGROUND

Sinonasal undifferentiated carcinoma (SNUC) is an uncommon malignancy of the nasal cavity and accessory sinuses with limited available studies evaluating role of induction chemotherapy (IC), demographics, and socioeconomic factors on overall survival (OS).

METHODS

The 2004-2015 National Cancer Database was queried for patients with histologically confirmed SNUC. IC was defined as chemotherapy administered 6 months to 2 weeks before surgery or ≥45 days before radiotherapy.

RESULTS

Of 440 identified patients, 70 (16%) underwent treatments involving IC. This consisted of 52 (12%), 15 (3%), and 3 (1%) patients receiving IC before definitive radiation therapy, surgery and adjuvant radiotherapy, or surgery only, respectively. On univariate analysis, IC (p = 0.34) did not affect OS, whereas having government insurance (hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.37-2.34; p < 0.001) and living in regions with ≥13% of the population without a high school diploma (HR, 1.38; 95% CI, 1.06-1.79; p = 0.02) were associated with worse OS. On log-rank test, patients with advanced stage had similar OS regardless of whether or not they received IC (p = 0.96). Patients who received IC lived closer to their treatment site (p = 0.02) and had worse overall health, with more comorbidities (p = 0.02). The timing of IC before definitive surgery or radiation did not affect OS (p = 0.69).

CONCLUSION

In this SNUC population-based analysis, IC did not appear to provide additional OS benefit regardless of disease stage or timing before definitive treatment. Distance to treatment and level of comorbidities may be associated with receiving IC, whereas type of insurance and residence education level may impact SNUC OS, regardless of treatment.

Overexpression of nicotinamide N-methyltransferase in HSC-2 OSCC cell line: effect on apoptosis and cell proliferation

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is the most common malignancy of oral cavity. Despite advances in therapeutic approaches, the 5-year survival rate for oral cancer has not improved in the last three decades. Therefore, new molecular targets for early diagnosis and treatment of OSCC are needed. In the present study, we focused on the enzyme nicotinamide N-methyltransferase (NNMT). We have previously shown that enzyme expression is upregulated in OSCC and NNMT knockdown in PE/CA PJ-15 cells significantly decreased cell growth in vitro and tumorigenicity in vivo.

MATERIAL AND METHODS

To further explore the role of the enzyme in oral cancer cell metabolism, HSC-2 cells were transfected with the NNMT expression vector (pcDNA3-NNMT) and the effect of enzyme upregulation on cell proliferation was evaluated by MTT assay. Subsequently, we investigated at molecular level the role of NNMT on apoptosis and cell proliferation, by exploring the expression of β-catenin, survivin, and Ki-67 by real-time PCR. Moreover, we performed immunohistochemistry on 20 OSCC tissue samples to explore the expression level of NNMT and survivin ΔEx3 isoform.

RESULTS

Enzyme upregulation significantly increased cell growth in vitro. Moreover, a positive correlation between NNMT and survivin ΔEx3 isoform expression levels was found both in HSC-2 cells and in OSCC tissue samples.

CONCLUSION

Taken together, our results indicate a possible involvement of NNMT in the proliferation and tumorigenic capacity of OSCC cells and seem to suggest that the enzyme could represent a potential target for the treatment of oral cancer.

CLINICAL RELEVANCE

The involvement of NNMT in cell growth and anti-apoptotic mechanisms seems to suggest that this enzyme could be a new therapeutic target to improve the survival of OSCC patients.

Super-charged NK cells inhibit growth and progression of stem-like/poorly differentiated oral tumors in vivo in humanized BLT mice; effect on tumor differentiation and response to chemotherapeutic drugs

Therapeutic role of NK cells in solid tumors was challenged previously even though their role in hematological malignancies has clearly been established. Furthermore, functions and numbers of NK cells are greatly suppressed in oral cancer patients necessitating effective future NK immunotherapeutic strategies to aid in the control of disease. The humanized-BLT (hu-BLT) mice were used to implant stem-like/undifferentiated oral tumors to study the role of super-charged NK cells with and without feeding with AJ2 probiotic bacteria. Implanted CSC/undifferentiated tumors resected from NK-injected mice exhibited differentiated phenotype, grew slowly, and did not cause weight loss, whereas those from tumor-bearing mice without NK-injection remained relatively more stem-like/poorly-differentiated, grew faster, and caused significant weight loss. Moreover, in vitro NK-differentiated tumors were sensitive to chemotherapeutic drugs, and when implanted in the oral-cavity grew no or very small tumors in mice. When NK-mediated differentiation of tumors was blocked by IFN-γ and TNF-α antibodies before implantation, tumors grew rapidly, remained stem-like/poorly-differentiated and became resistant to chemotherapeutic drugs. Loss of NK cytotoxicity and decreased IFN-γ secretion in tumor-bearing mice in PBMCs, splenocytes, bone marrow derived immune cells and enriched NK cells was restored by the injection of super-charged NK cells with or without feeding with AJ2. Much greater infiltration of CD45⁺ and T cells were observed in tumors resected from the mice, along with the restored secretion of IFN-γ from purified T cells from splenocytes in NK-injected tumor-bearing mice fed with AJ2 probiotic bacteria. Thus, super-charged NK cells prevent tumor growth by restoring effector function resulting in differentiation of CSCs/undifferentiated-tumors in hu-BLT mice.

Targeting oral cancer stemness and chemoresistance by isoliquiritigenin-mediated GRP78 regulation

Cancer stem cells (CSCs) are cells that drive tumorigenesis, contributing to metastasis and cancer recurrence as well as resistance to chemotherapy of oral squamous cell carcinomas (OSCC). Therefore, approaches to target CSCs become the subject of intense research for cancer therapy. In this study, we demonstrated that isoliquiritigenin, a chalcone-type flavonoid isolated from licorice root, exhibited more toxicity in oral cancer stem cells (OSCC-CSCs) compared to normal cells. Treatment of isoliquiritigenin not only inhibited the self-renewal ability but also reduced the expression of CSC markers, including the ALDH1 and CD44. In addition, the capacities of OSCC-CSCs to invade, metastasize and grow into a colony were suppressed by isoliquiritigenin. Most importantly, we showed that isoliquiritigenin potentiated chemotherapy along with downregulated expression of an ABC transporter that is associated with drug resistance, ABCG2. Moreover, a combination of isoliquiritigenin and Cisplatin significantly repressed the invasion and colony formation abilities of OSCC-CSCs. Our results suggested that administration of isoliquiritigenin reduced the protein expression of mRNA and membrane GRP78, a critical mediator of tumor biology. Overexpression of GRP78 reversed the inhibitory effect of isoliquiritigenin on OSCC-CSCs. Furthermore, isoliquiritigenin retarded the tumor growth in nude mice bearing OSCC xenografts. Taken together, these findings showed that isoliquiritigenin is an effective natural compound that can serve as an adjunct to chemotherapy for OSCC.

Berberine-targeted miR-21 chemosensitizes oral carcinomas stem cells

Cancer recurrence and chemoresistance are two major obstacles to the treatment of oral squamous cell carcinomas (OSCC). And cancer stem cells (CSCs) have been found to possess tumor initiating, self-renewal and metastasis abilities, resulting in the relapse and chemoresistance of OSCC. In the present study, we investigated the anti-CSCs effect of berberine, a phenanthrene alkaloid isolated from the Berberis genus. Our results demonstrated that berberine dose dependently downregulated the oncogenicity in vitro, including ALDH1 activity, self-renewal property, and colony formation and invasion abilities as well as potentiated chemosensitivity of OSCC-CSCs. In addition, tumor growth in mice was attenuated after oral gavage treatment of berberine. We showed that the expression of miR-21 was suppressed following administration of berberine in OSCC-CSCs. And inhibition of endogenous miR-21 reduced the characteristics of CSCs, including self-renewal, migration, invasion capabilities and ALDH1 activity. Taken together, we demonstrated the anti-CSC effect of berberine in oral cancer and its potential to serve as adjuvant to traditional chemotherapy to improve treatment effect.

GMI ablates cancer stemness and cisplatin resistance in oral carcinomas stem cells through IL-6/Stat3 signaling inhibition

Cancer stem cells (CSCs) have been identified to exert tumor-initiating ability, resulting in the recurrence, metastasis and chemoresistance of oral squamous cell carcinomas. In the present study, we showed that GMI, an immunomodulatory protein from Ganoderma microsporum, induc ed a cytotoxic effect in oral carcinomas stem cells (OCSCs). Treatment of GMI dose-dependently inhibited the expression of CSC markers, including ALDH1 activity and CD44 positivity. Moreover, GMI suppressed the self-renewal property, colony formation, migration, and invasion abilities as well as potentiated chemo-sensitivity in OCSCs. Our results suggested that the tumor suppressive effect of GMI was mediated through inhibition of IL-6/Stat3 signaling pathway. Furthermore, tumor growth was reduced in mice bearing xenograft tumors after oral administration of GMI. Taken together, we demonstrated the anti-CSC effect of GMI in oral cancer and GMI may serve as a natural cisplatin adjuvant to prevent cancer recurrence.

Activation of microRNA-494-targeting Bmi1 and ADAM10 by silibinin ablates cancer stemness and predicts favourable prognostic value in head and neck squamous cell carcinomas

Tumor initiating cells (TICs) possessing cancer stemness were shown to be enriched after therapy, resulting in the relapse and metastasis of head and neck squamous cell carcinomas (HNC). An effective therapeutic approach suppressing the HNC-TICs would be a potential method to improve the treatments for HNC. We observed that the treatment of silibinin (SB) dose dependently down-regulated the ALDH1 activity, CD133 positivity, stemness signatures expression, self-renewal property, and chemoresistance in ALDH1+CD44+ HNC-TICs. Using miRNA-microarray and mechanistic studies, SB increased the expression of microRNA-494 (miR-494) and both Bmi1 and ADAM10 were identified as the novel targets of miR-494. Moreover, overexpression of miR-494 results in a reduction in cancer stemness. However, knockdown of miR-494 in CD44⁻ALDH1⁻non-HNC-TICs enhanced cancer stemness and oncogenicity, while co-knockdown of Bmi1 and ADAM10 effectively reversed these phenomena. Mice model showed that SB treatment by oral gavage to xenograft tumors reduced tumor growth and prolonged the survival time of tumor-bearing mice by activation of miR-494-inhibiting Bmi1/ADAM10 expression. Survival analysis indicated that a miR494^highBmi1^lowADAM10^low phenotype predicted a favourable clinical outcome. We conclude that the inhibition of tumor aggressiveness in HNC-TICs by SB was mediated by up-regulation miR-494, suggesting that SB would be a valuable anti-cancer drug for treatment of HNC.

xCT expression modulates cisplatin resistance in Tca8113 tongue carcinoma cells

Tongue squamous cell carcinoma (TSCC), which is a subtype of head and neck cancer, is the most common type of oral cancer. Due to its high recurrence rate and chemoresistance, the average survival rate for patients with TSCC remains unsatisfactory. At present, cisplatin (CDDP) is utilized as the first-line treatment for numerous solid neoplasms, including TSCC. CDDP resistance develops in the majority of patients; however, the mechanism of such resistance remains unknown. Therefore, the present study aimed to clarify the mechanism of CDDP resistance and attempted to reduce chemoresistance. The results indicated that CDDP significantly increased expression of xCT, which is the light chain and functional subunit of the glutamate/cysteine transporter system x_c^-, and a subsequent increase in glutathione (GSH) levels was observed. The present study demonstrated that the upregulation of xCT expression and intercellular GSH levels contributed to CDDP resistance in TSCC cells. Furthermore, xCT suppression, induced by small interfering RNA or pharmacological inhibitors, sensitized TSCC cells to CDDP treatment. In conclusion, the present study revealed that CDDP-induced xCT expression promotes CDDP chemoresistance, and xCT inhibition sensitizes TSCC cells to CDDP treatment. These results provide a novel insight into the molecular mechanisms involved in TSCC cell chemoresistance.

Effect of polypharmacy and potentially inappropriate medications on treatment and posttreatment courses in elderly patients with head and neck cancer

PURPOSE

The use of excessive and inappropriate medications is a common problem in elderly populations. The use of polypharmacy (PP) and potentially inappropriate medication (PIM) may affect treatment-related morbidities in elderly cancer patients, which has rarely been studied in patients with head and neck cancer (HNC). Here, we evaluate the effects of PP and PIM on treatment and posttreatment courses in elderly HNC patients.

METHODS

This study included 229 elderly HNC patients who underwent definitive treatment. Medications were carefully recorded, and the prevalences of PP and PIM are reported. We evaluated the associations between PP, PIM, treatment, and posttreatment course in terms of comorbidities, treatment-related toxicity, prolonged hospitalization, and posttreatment noncancer health events.

RESULTS

The prevalences of PP and PIM in our elderly HNC patients were 29.3 and 24.0 %, respectively, and frequently described PIMs include aspirin (12.2 %), calcium channel blockers (4.8 %), benzodiazepines (4.3 %), and nonsteroidal anti-inflammatory drugs (3.9 %). PP and PIM were not significantly associated with treatment-related toxicity, but were associated with modestly increased prolonged hospitalization [odds ratio [OR] 2.30 (95 % confidence interval 0.89-5.95); P = 0.080] and noncancer health events [OR 1.81 (0.99-3.31); P = 0.052], respectively. Among high-risk medications, benzodiazepine [OR 5.09 (1.21-21.5); P = 0.015] and calcium channel blockers [OR 5.69 (1.07-33.25); P = 0.031) were significantly associated with prolonged hospitalization.

CONCLUSIONS

Neither PP nor PIM are significantly associated with treatment-related toxicity in elderly HNC patients, but these are associated with modest increases in prolonged hospitalization and noncancer health events.

Antitumor effect of TRAIL on oral squamous cell carcinoma using magnetic nanoparticle-mediated gene expression

We developed a new magnetic nanovector to improve the efficiency and targeting of transgene therapy for oral squamous cell carcinoma (OSCC). Positively charged polymer PEI-modified Fe(3)O(4) magnetic nanoparticles were tested as gene transfer vectors in the presence of a magnetic field. The Fe(3)O(4) nanoparticles were prepared by a co-precipitation method and had good dispersibility in water. These nanoparticles modified by PEI were combined with negatively charged pACTERT-EGFP via electrostatic interaction. The transfection efficiency of the magnetic nano-gene vector with the magnetic field was determined by a fluorescence-inverted microscope and flow cytometry. The results showed significant improvement compared with the control group (p < 0.05). The magnetic complexes also exhibited up to 6-times higher transfection efficiency compared with commonly used PEI or lipofectin. On the basis of these results, the antitumor effect with suicide gene therapy using pACTERT-TRAIL in vitro and vivo was evaluated. In vitro apoptosis was determined with the Annexin V-FITC Apoptosis Detection Kit. The results suggested that PEI-modified Fe(3)O(4) nanoparticles could mediate the killing of Tca83 cells. Furthermore, treatment with pACTERT-TRAIL delivered by magnetic nanoparticles showed a significant cytostatic effect through the induction of apoptosis in a xenograft model. This indicates that magnetic nano-gene vectors could improve the transgene efficiency for Tca83 cells and could exhibit antitumor functions with the plasmid pACTERT-TRAIL. This may be a new way to treat OSCC.

Chemotherapy advances in locally advanced head and neck cancer

The management of locally advanced unresectable head and neck squamous cell cancer (HNSCC) continues to improve. One of the major advances in the treatment of HNSCC was the addition of chemotherapy to radiation in the treatment of non-surgical patients. The majority of the data regarding chemotherapy in HNSCC involve cisplatin chemotherapy with concurrent radiation. However, several new approaches have included targeted therapy against epidermal growth factor receptor and several recent studies have explored the role of induction chemotherapy in the treatment of HNSCC. The purpose of this article is to provide an overview of the role of chemotherapy in the treatment of locally advanced HNSCC.

The effect of induction chemotherapy on tumor volume and organ-at-risk doses in patients with locally advanced oropharyngeal cancer

BACKGROUND AND PURPOSE

To retrospectively report changes in gross tumor volume (GTV) and organ-at-risk (OAR) doses after induction chemotherapy (IC) in oropharyngeal cancer using different contouring strategies.

MATERIALS AND METHODS

GTV and OARs were delineated on pre- and post-IC planning CT. Two post-IC GTV contours were made: (1) a 'consensus set' using published guidelines (GTVconsensus), and (2) 'visible set', delineating only visible post-IC GTV (GTVvisible). Pre-IC interactively optimized volumetric modulated arc therapy plans were generated. The pre-IC planning constraints served as the starting point for both post-IC plans. Results reflect pooled data from all 10 patients.

RESULTS

Mean reduction in volume post-IC was 24% and 47% for consensus and visible primary tumor and 57% and 60% for consensus and visible nodes. Compared to pre-IC plans, average mean OAR dose for post-IC GTVconsensus plans was significantly lower for CL parotid. For GTVvisible plans both parotids, upper/lower larynx, inferior pharyngeal constrictor and cricopharyngeal muscles were significantly lower. However reductions compared with post-IC GTVconsensus plans were modest (1.6/1.5/1.2/3.7/5.9/2.6Gy, respectively).

CONCLUSION

IC in patients with oropharyngeal carcinoma results in substantial reductions in GTVs. If post-IC GTVs are used, which is contrary to current consensus, statistically significant but relatively small OAR dose reductions are observed.

Comparison of quality of life in head and neck stage IV squamous cell cancer patients treated with surgery and reconstruction versus radical radiotherapy

This study aimed to analyze the differences in quality of life (QOL) in head and neck stage IV squamous cell cancer patients treated with surgery and reconstruction versus radical radiotherapy.The QOL was analyzed in 2 groups of patients. All patients had the same demographic and oncologic features but were treated differently. Group 1 (n = 16) was compound with patients treated with surgery and radiotherapy, whereas group 2 (n = 14) was formed with those who received radical radiotherapy. The University of Washington questionnaire was used for this purpose.A total of 30 questionnaires were received. The total score of the questionnaires ranged from 485 to 1120. The mean values were 837.8 for group 1 and 827.85 for group 2, with no statistical significance. Significant differences were found in several domains. By using a validated questionnaire, it is possible to estimate the impact in QOL of these patients.

Fighting cancer from different signalling pathways: Effects of the proteasome inhibitor Bortezomib in combination with the polo-like-kinase-1-inhibitor BI2536 in SCCHN

Inhibition of the proteasome with Bortezomib as well as inhibition of Polo-like-kinase-1 (PLK-1) has been shown to be effective in many solid tumour models and also in squamous cell carcinoma of the head and neck (SCCHN) cell lines. For the first time, we systematically examined the antitumour effect of Bortezomib in combination with BI2536 in SCCHN in an in vitro study. Dose escalation studies were performed with nine SCCHN cell lines using Bortezomib and BI2536 as single agent and combination treatments. Growth-inhibitory and pro-apoptotic effects were measured quantitatively using cytohistology and Human Apoptose Array kit. The combination of Bortezomib and BI2536 showed significant anti-proliferative and apoptotic activity in all SCCHN cell lines investigated (P=0.008) compared to both the untreated control group and Bortezomib alone. A combination treatment regime consisting of the proteasome inhibitor, Bortezomib, and the inhibitor of PLK-1, BI2536, leads to an enhanced anti-proliferative and apoptotic effect in SCCHN cell lines, compared to single agent treatment with Bortezomib alone.

Epithelial-mesenchymal transition transcription factor ZEB1/ZEB2 co-expression predicts poor prognosis and maintains tumor-initiating properties in head and neck cancer

OBJECTIVES

Both epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties may be involved in metastasis, which contributes to the high mortality rate of patients with head and neck cancers (HNCs). However, the mechanisms through which the EMT transcription factors ZEB1 and ZEB2 regulate HNC are still unclear.

METHODS

Tumor initiating capability of HNC-CH133(+) cells with ZEB1/2 knockdown or co-overexpression was presented in vitro and in vivo.

RESULTS

In the present study, we demonstrated that ZEB1/ZEB2 expression was significantly increased in HNC-CD133(+) CSC-like cells compared with HNC-CD133(-) cells. The small interfering RNA (siRNA)-mediated co-knockdown of ZEB1 and ZEB2 (siZEB1/2) in HNC-CH133(+) cells suppressed their CSC-like properties, including self-renewal ability, the expression of stemness markers, and drug resistance. In contrast, the co-overexpression of ZEB1/ZEB2 in HNC-CD133(-) cells enhanced their sphere-forming ability and increased the percentage of CD44-positive cells and side population cells. In vivo studies showed that the delivery of siZEB1/2 to xenograft tumors in nude mice reduced tumor growth and the rate of distant metastasis. In clinical samples, the levels of ZEB1/ZEB2 expression were low in local lesions but high in metastatic lymph nodes in HNC tissues. Patients with tumors that co-expressed ZEB1(high) and ZEB2(high) had especially poor survival rates.

CONCLUSION

Therapies targeting ZEB1/ZEB2 in HNC-CD133(+) cells may provide a new approach for HNC therapy in the future.

Targeting proliferation and survival pathways in head and neck cancer for therapeutic benefit

Head and neck squamous cell carcinomas (HNSCC) are common human malignancies with poor clinical outcomes. The 5-year survival rates for patients with advanced stage HNSCC have not changed appreciably in the past few decades, underscoring a dire need for improved therapeutic options. Recent studies have elucidated a key signaling axis, the EGFR-STAT3-Bcl-XL signaling axis, that is aberrantly activated in a majority of HNSCC and contributes to the proliferation and survival of malignant cells. Considerable effort is being placed on developing highly specific inhibitors of different components of this pathway. This review highlights the progress that is being made towards achieving potent inhibition of the EGFR-STAT3-Bcl-XL signaling axis in HNSCC and the promising therapeutic strategies that are currently under development for this disease.

Circulating tumour cells in locally advanced head and neck cancer: preliminary report about their possible role in predicting response to non-surgical treatment and survival

BACKGROUND AND PURPOSE

The mechanism of dissemination of locally advanced head and neck cancer (LAHNC) is far to be resolved. Circulating tumour cells (CTC) have been identified as a prognostic factor in metastatic breast and prostate cancer. This prospective multi-centric analysis studied the possible role of CTC identification in LAHNC.

MATERIALS AND METHODS

CTC were searched in 73 patients with LAHNC (oropharynx, n=39; nasopharynx, n=10; larynx, n=10; paranasal sinuses, n=6, of whom 3 with sinonasal undifferentiated carcinoma, SNUC; hypopharynx, n=5; oral cavity, n=3). All of them (apart from SNUC) had squamous cell cancers. The relationship between CTC positivity and other clinical prognostic factors has been investigated. Response to treatment and survival has been related with changes in CTC number during the treatment.

RESULTS

CTC were frequently identified in oro- and hypopharyngeal cancer and in SNUC. They were more frequent in stage IV than in stages I-III disease (18% versus 6%, p=NS (not significant)). Partial or complete response (CR) was related with the absence or disappearance of CTC during treatment (p=0.017). A decrease in the CTC number or their absence throughout the treatment seems also related with non-progressive disease, after both complete or incomplete remission and with the proportion of patients alive and NED (no evidence of disease) (p=0.009).

CONCLUSIONS

These preliminary data suggest a possible role of CTC determination in head and neck cancer. Additional and longer follow up data need to be collected to confirm these findings.

Overexpression of the DNA sensor proteins, absent in melanoma 2 and interferon-inducible 16, contributes to tumorigenesis of oral squamous cell carcinoma with p53 inactivation

The development of oral squamous cell carcinoma (OSCC) is a multistep process that requires the accumulation of genetic alterations. To identify genes responsible for OSCC development, we performed high-density single nucleotide polymorphism array analysis and genome-wide gene expression profiling on OSCC tumors. These analyses indicated that the absent in melanoma 2 (AIM2) gene and the interferon-inducible gene 16 (IFI16) mapped to the hematopoietic interferon-inducible nuclear proteins. The 200-amino-acid repeat gene cluster in the amplified region of chromosome 1q23 is overexpressed in OSCC. Both AIM2 and IFI16 are cytoplasmic double-stranded DNA sensors for innate immunity and act as tumor suppressors in several human cancers. Knockdown of AIM2 or IFI16 in OSCC cells results in the suppression of cell growth and apoptosis, accompanied by the downregulation of nuclear factor kappa-light-chain-enhancer of activated B cells activation. Because all OSCC cell lines have reduced p53 activity, wild-type p53 was introduced in p53-deficient OSCC cells. The expression of wild-type p53 suppressed cell growth and induced apoptosis via suppression of nuclear factor kappa-light-chain-enhancer of activated B cells activity. Finally, the co-expression of AIM2 and IFI16 significantly enhanced cell growth in p53-deficient cells; in contrast, the expression of AIM2 and/or IFI16 in cells bearing wild-type p53 suppressed cell growth. Moreover, AIM2 and IFI16 synergistically enhanced nuclear factor kappa-light-chain-enhancer of activated B cells signaling in p53-deficient cells. Thus, expression of AIM2 and IFI16 may have oncogenic activities in the OSCC cells that have inactivated the p53 system.

Bortezomib induces autophagy in head and neck squamous cell carcinoma cells via JNK activation

The molecular mechanism of autophagy induction following proteasome inhibition is not fully understood. We report that the proteasome inhibitor bortezomib potently induces autophagy in head and neck squamous cell carcinoma (HNSCC) cells, as demonstrated by autophagosome formation and induction of complete autophagic flux. Bortezomib treatment led to phosphorylation/activation of jun N-terminal kinase (JNK) enzymes and JNK-dependent phosphorylation of Bcl-2 on serine 70. Pharmacologic inhibition of JNK, but not p38 MAPK, dramatically inhibited bortezomib induction of autophagy regulatory proteins and autophagosome formation. These results demonstrate a key requirement for JNK signaling in the activation of autophagy by bortezomib.

Neck dissection can be avoided after sequential chemoradiotherapy and negative post-treatment positron emission tomography-computed tomography in N2 head and neck squamous cell carcinoma

AIMS

This study assessed neck control in patients with N2 head and neck squamous cell carcinoma (HNSCC) treated with sequential chemoradiotherapy (SCRT) and the incidence of neck recurrence when neck dissection was withheld in those with negative post-treatment fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET).

MATERIALS AND METHODS

Thirty-four consecutive patients with N2 HNSCC who were treated with radical intent using SCRT were included. Twenty-seven patients received concomitant platinum-based chemotherapy with their radiotherapy. Nineteen patients were treated with intensity-modulated radiotherapy. PET-computed tomography (PET-CT) was obtained 3 months after the completion of radical radiotherapy. Neck dissection was carried out only in those with increased FDG uptake in the neck.

RESULTS

The median follow-up was 39.1 months. One patient had increased FDG uptake in the neck post-treatment, which was false positive for malignancy. The remaining 33 patients were observed without neck dissection. No regional recurrence occurred. The negative predictive value (NPV) of post-treatment PET-CT was 100%.

CONCLUSIONS

Good disease control in the neck can be achieved in patients with N2 HNSCC with SCRT. Post-treatment PET-CT has a high NPV. Neck dissection can be avoided if post-treatment PET-CT is negative.

Induction chemotherapy response and recurrence rates in correlation with N0 or N+ stage in oral squamous cell cancer (OSCC)

The authors compared N0 with N+ cases in neoadjuvant chemotherapy regression and recurrence. During a 12-year period, 180 consecutive oral squamous cell cancer patients were observed. Of these patients, 78 were N0 and 102 N+ stages. The drugs used were as follows: bleomycin, vincristine, methotrexate, and mitolactol. After three courses of chemotherapy, the regression (complete response (CR), partial response (PR), and no response (NR)) and side effect rate were determined. All patients were operated on and observed for the number and localization of recurrences during 3 year follow-up time. The N0 cases came from T2-3, while N+ was from T2-4a (AJCC 2002). The regression in the N0 group was CR 46%, PR 53%, and NR 1%; but in the N+ group, it was CR 12%, PR 72%, and NR 16%. The regression rate was significantly higher (p = 0.00025) for N0 group than N+ group. The regression rate for T3 N0 was significantly higher (p = 0.055) than for T3 N+ cases. In the N0 stage, the regression rate was significantly higher (p = 0.0174) for T2 than T3. In N+ stage, there was no significant difference (p = 0.183) for T2-4a. The side effects were slight. The recurrence rate for the N0 group was significantly lower (15%, p = 0.000069), while for N+ group, it was 59%. The dependence in the T3 cases was also significant (p = 0.009) in the 3-year tumor-free survival. The N stage seems a more important prognostic factor for chemotherapy response and recurrence rate than the T stage. Stage III can be divided into subgroups without metastasis (III.a) and with metastasis (III.b.), based on significant difference in regression and recurrence rate.

Evidence-based organ-sparing radiotherapy in head and neck cancer

Intensification of radiotherapy treatment for locally advanced head and neck cancer by use of altered fractionation schedules or concomitant chemotherapy has resulted in substantially improved locoregional control and survival. However, these improvements have come at the cost of increased acute, and late, toxic effects. The application of technological advances, such as intensity-modulated radiotherapy, is expected to further improve the therapeutic index of radiotherapy for head and neck cancer, by limiting toxicity and possibly by increasing locoregional control. However, the organ-sparing potential of such highly conformal radiotherapy techniques relies heavily on the appropriate selection and accurate delineation of the crucial organs at risk, with the application of rigorous dose constraints during planning. Because xerostomia and dysphagia are the main causes of decreased quality of life after radiotherapy for head and neck cancer, the prevention of these two complications will form the focus of this review.

Toxicity of head-and-neck radiation therapy in human immunodeficiency virus-positive patients

PURPOSE

To examine the acute morbidity of high dose head and neck RT and CRT in patients with infected with HIV.

METHODS AND MATERIALS

All HIV-positive patients who underwent radiation therapy for head and neck cancer in our department between 2004 and 2008 were reviewed. Treatment related data were examined. All treatments were delivered with megavoltage photon beams or electron beams. Patients were evaluated by an attending radiation oncologist for toxicity and response on a weekly basis during therapy and monthly after treatment in a multidisciplinary clinic. Acute toxicities were recorded using the Radiation Therapy and Oncology Group (RTOG) common toxicity criteria. Response to treatment was based on both physical exam as well as post-treatment imaging as indicated.

RESULTS

Thirteen patients who underwent RT with a diagnosis of HIV were identified. Median age was 53 years and median follow-up was 22 months. Twelve had squamous cell carcinoma and one had lymphoproliferative parotiditis. Median radiation dose was 66.4 Gy and median duration of treatment was 51 days. The median number of scheduled radiotherapy days missed was zero (range 0 to 7). One patient (8%) developed Grade 4 confluent moist desquamation. Eight patients (61%) developed Grade 3 toxicity.

CONCLUSION

Based on our results, HIV-positive individuals appear to tolerate treatment for head and neck cancer, with toxicity similar to that in HIV-negative individuals.

NDRG2 is a candidate tumor-suppressor for oral squamous-cell carcinoma

Oral cancer is one of the most common cancers worldwide, and squamous-cell carcinoma (OSCC) is the most common phenotype of oral cancer. Although patients with OSCC have poor survival rates and a high incidence of metastasis, the molecular mechanisms of OSCC development have not yet been elucidated. This study investigated whether N-myc downstream-regulated gene 2 (NDRG2) contributes to the carcinogenesis of OSCC, as NDRG2 is reported to be a candidate tumor-suppressor gene in a wide variety of cancers. The down-regulation of NDRG2 mRNA, which was dependent on promoter methylation, was seen in the majority of OSCC cases and in several cases of precancerous leukoplakia with dysplasia. Induction of NDRG2 expression in an HSC-3/OSCC cell line significantly inhibited cell proliferation and decreased colony formation ability on soft agar. The majority of OSCC cell lines showed an activation of PI3K/Akt signaling, and enforced expression of NDRG2 in HSC-3 cells decreased the level of phosphorylated Akt at Serine 473 (p-Akt). Immunohistochemical p-Akt staining was detected in 56.5% of the OSCC tumors, and 80.4% of the tumors were negative for NDRG2 staining. Moreover, positive p-Akt staining was inversely correlated with decreased NDRG2 expression in OSCC tumors with moderate to poor differentiation (p<0.005). Therefore, NDRG2 is a candidate tumor-suppressor gene for OSCC development and probably contributes to the tumorigenesis of OSCC partly via the modulation of Akt signaling.

Platin-based exclusive chemotherapy for selected patients with squamous cell carcinoma of the larynx and pharynx

BACKGROUND

The current study was conducted to determine the long-term outcomes of patients with squamous cell carcinoma of the larynx and pharynx who were treated with platin-based exclusive chemotherapy (EC) after they achieved a complete clinical response (CCR) to induction chemotherapy.

METHODS

One hundred forty-two who achieved a CCR after platin-based induction chemotherapy were treated exclusively with additional chemotherapy, and 98.6% were followed for a minimum of 3 years or until death. Thirty-five patients had >10 years of follow-up.

RESULTS

The survival rates at 1 year and 5 years were 95.8% and 61.2%, respectively. The main causes of death were metachronous second primary tumors (n = 27) and intercurrent disease (n = 21). Death related to EC was not encountered, and only 2 patients (1.4%) had grade 4 toxicity. In multivariate analysis, primary tumor arising outside the glottic larynx (P = .0001) and a Charlson comorbidity index >1 (P = .0001) were associated with a statistically significant reduction in survival. The 1-year and 5-year Kaplan-Meier local control estimates were 76.1% and 50.7%, respectively. Salvage treatment resulted in an observed final local control rate of 93% that varied from 97.2% in patients who had glottic cancer to 88.7% in patients who had tumor originating from other sites (P = .097). Combined chemotherapy with cisplatin and 5-fluorouracil (PF) allowed for the successful modulation of local therapy in 54.9% of patients.

CONCLUSIONS

For selected patients, EC may provide long-term, durable disease control. For patients who developed recurrent disease after EC, this approach did not diminish survival and maintained function in the majority of patients. Future work should be directed toward select markers of response to PF chemotherapy with which to identify those patients who are suited optimally for this approach.

Bortezomib up-regulates activated signal transducer and activator of transcription-3 and synergizes with inhibitors of signal transducer and activator of transcription-3 to promote head and neck squamous cell carcinoma cell death

Head and neck squamous cell carcinomas (HNSCC) are commonly resistant to conventional chemotherapy drugs and exhibit overexpression of signal transducer and activator of transcription 3 (STAT3). STAT3 promotes both the proliferation and survival of HNSCC cells. Recent studies have shown that the proteasome inhibitor bortezomib shows cytotoxic activity against HNSCC in vitro and in vivo. We report that treatment of HNSCC cells with bortezomib led to up-regulation of total STAT3 protein and the phosphorylated/activated form of STAT3, as well as an increase in cellular STAT3 activity. This suggested that the ability of bortezomib to kill HNSCC cells may be blunted due to induction of STAT3, and inhibition of STAT3 may be a useful means for improving bortezomib efficacy. Indeed, forced expression of dominant-active STAT3 inhibited bortezomib-induced cell death, whereas expression of dominant-negative STAT3 served to enhance killing by this compound. In addition, specific inhibition of STAT3 with the use of a STAT3 decoy oligonucleotide resulted in enhancement of bortezomib-induced apoptosis signaling and loss of clonogenic survival. Cotreatment of HNSCC cells with bortezomib and guggulsterone, a naturally occurring compound known to inhibit STAT3 activation, led to synergistic activation of cell death and loss of clonogenic survival. In summary, these studies show that bortezomib induces the expression of active STAT3, a key growth- promoting protein in HNSCC cells. Furthermore, our findings suggest that the therapeutic activity of bortezomib against HNSCC may be markedly improved by cotreatment with molecular targeting agents against STAT3.

Neoadjuvant chemotherapy for locally advanced squamous cancers of the head and neck: current status and future prospects

PURPOSE OF REVIEW

To assess the role of neoadjuvant chemotherapy for locally advanced squamous head and neck cancer.

RECENT FINDINGS

Several phase III clinical trials in locally advanced squamous head and neck cancer show promising results for neoadjuvant platinum, taxane, and fluorouracil chemotherapy prior to definitive radiation or concurrent chemoradiation.

SUMMARY

Clinical trials comparing cisplatin and 5-fluorouracil with or without a taxane followed by radiation or concurrent chemoradiation show that the three-drug induction chemotherapy may improve survival particularly for unresectable tumors. Clinical trials comparing chemoradiation with and without induction three-drug chemotherapy are ongoing. Molecular and clinical considerations for using neoadjuvant chemotherapy in the treatment of locally advanced head and neck cancers are being explored.

Treatment of head and neck cancers: issues for clinical pharmacists

Head and neck cancers are a heterogeneous group of diseases involving the oral cavity, pharyngeal tube, and larynx. Given the drug therapy options available, clinical pharmacists can play an important role in the care of this patient population. They can recommend a regimen based on efficacy, toxicity, and patient-specific factors; ensure that the prescribed regimen has been studied and reported in the literature; verify dosages; and monitor and counsel patients about adverse effects. Chemotherapy plus radiation (chemoradiation) is often the standard treatment for patients with stage III or nonmetastatic stage IV head and neck cancer. Cisplatin-based regimens are preferred, although carboplatin may be appropriate in some circumstances. Induction therapy with a docetaxel-based regimen is recommended for some patients; however, this therapy has been associated with a high frequency of grade 3 and 4 neutropenia and febrile neutropenia. Cetuximab, an epidermal growth factor receptor inhibitor, is the newest agent approved for treatment of head and neck cancer. Although evidence supports cetuximab combined with cisplatin versus cisplatin alone for patients with metastatic disease, the role of combination therapy is less clear in patients undergoing chemoradiation. Patients with head and neck cancer may experience swallowing difficulties or mouth pain, possibly interfering with drug administration and adherence; thus, pharmacists in all practice settings should be knowledgeable about different regimens and alternative routes of administration. Xerostomia and mucositis are common adverse effects of radiation therapy, and it is critical that good oral hygiene practices are maintained. Patients may achieve symptomatic relief from xerostomia with saliva substitutes, and clinical experience suggests that use of pilocarpine is worthwhile. Until more evidence becomes available, prevention of xerostomia and mucositis with amifostine is still controversial. Salt-water rinses, bioadherent oral gel, and honey are relatively inexpensive and nontoxic agents for managing mucositis. Because of the expense of palifermin, it is best reserved for refractory cases. Skin toxicities are common with radiation. Rash is also a common adverse effect of cetuximab. When used together, they may produce complicated skin toxicities. It is important to become familiar with the grading of these rashes so that appropriate therapy can be recommended. As pharmacotherapy for head and neck cancers continues to evolve, clinical pharmacists will continue to have an important role in optimizing treatment for patients by balancing efficacy and toxicity.

ABT-737 synergizes with chemotherapy to kill head and neck squamous cell carcinoma cells via a Noxa-mediated pathway

Overexpression of Bcl-X(L), an antiapoptotic Bcl-2 family member, occurs in a majority of head and neck squamous cell carcinomas (HNSCCs) and correlates with chemotherapy resistance in this disease. Overexpression of Bcl-2 is also observed in HNSCC, albeit less frequently. We have previously shown that peptides derived from the BH3 domains of proapoptotic proteins can be used to target Bcl-X(L) and Bcl-2 in HNSCC cells, promoting apoptosis. In this report, we examined the impact of ABT-737 (for structure, see Nature 435: 677-681, 2005 ), a potent small-molecule inhibitor of Bcl-X(L) and Bcl-2, on HNSCC cells. As a single agent, ABT-737 was largely ineffective at promoting HNSCC cell death. By contrast, ABT-737 strongly synergized with the chemotherapy drugs cisplatin and etoposide to promote HNSCC cell death and loss of clonogenic survival. Synergism between ABT-737 and chemotherapy was associated with synergistic activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase. Treatment with ABT-737 plus chemotherapy resulted in dramatic up-regulation of proapoptotic Noxa protein, and small interfering RNA (siRNA)-mediated inhibition of Noxa up-regulation partially attenuated cell death by the synergistic combination. Treatment with cisplatin or etoposide, alone or in combination with ABT-737, resulted in substantial down-regulation of Mcl-1L, a known inhibitor of ABT-737 action. Further down-regulation of Mcl-1L using siRNA failed to enhance killing by the cisplatin/ABT-737 synergistic combination, indicating that chemotherapy treatment of HNSCC cells is sufficient to remove this impediment to ABT-737. Together, our results demonstrate potent synergy between ABT-737 and chemotherapy drugs in the killing of HNSCC cells and reveal an important role for Noxa in mediating synergism by these agents.

[Organ sparing treatment modalities - which type of treatment for which carcinoma?]

Radical surgery followed by postoperative radiotherapy is still the most effective treatment option for advanced resectable head and neck cancer. It is therefore of utmost importance to determine the resectability before start of the treatment. For those patients who suffer from unresectable cancer or refuse to undergo surgery, alternatives, such as induction-chemotherapy or radiotherapy plus chemotherapy alone may be offered. Historical studies investigating alternative treatment protocols were conducted almost 20 years ago. These studies demonstrated that in approximately 2/3 of all patients with laryngeal and hypopharyngeal cancer undergoing induction-chemotherapy according to the PF-protocol (cisplatin plus 5-FU as a continuous infusion) and subsequent radiotherapy, larynx preservation without negative impact on overall survival could be achieved. At least three randomized studies have shown a clinical advantage for a treatment combination consisting of docetaxel or paclitaxel plus CDDP/5-FU over a historical control regimen containing CDDP/5-FU alone. This novel combination therefore is currently regarded as the gold-standard for induction-chemotherapy in advanced head and neck cancer patients. A further significant addition to the therapeutic armamentarium for the head and neck radiation oncologist is the recently introduced monoclonal antibody cetuximab. It was found in a randomized landmark study that addition of cetuximab to radiotherapy significantly improves local control as well as overall survival of advanced stage head and neck cancer patients. In light of these recent developments this review discusses the role of organ sparing treatment protocols and different levels of evidence with special consideration of tumor localization.

Pretreatment with 5-FU enhances cisplatin cytotoxicity in head and neck squamous cell carcinoma cells

PURPOSE

In the treatment of head and neck malignancy, cisplatin and 5-FU have been used the most as chemotherapeutic agents. The difference in efficacies of these is unclear and controversial. To investigate more effective schedule, we analyzed the cytotoxicity in different treatment sequence with two agents in vitro and the mechanism for different effectiveness.

METHODS

UM-SCC-23 and UM-SCC-81B, head and neck squamous cell carcinoma cell lines, were analyzed for cellular killing in alternative sequence treatment with cisplatin and 5-FU. The treatment schedule was designed based on the clinical regimen. To determine the mechanism for the difference of cytotoxicity with each schedule, cell cycle distributions of both cells after 5-FU treatment with various durations were analyzed by flow-cytometry and immunostaining with anti-PCNA and anti-BrdU.

RESULTS

5-FU pretreatment followed by cisplatin treatment showed higher cell killing in both types of cells than the reverse treatment schedule. In the cell cycle analysis and immunostaining after the treatment of 5-FU, the rate of PCNA-positive cells was increased from 24 to 144 h in both cells. The rate of BrdU-positive cells of UM-SCC-81B in flow-cytometry was also increased, while that of UM-SCC-23 was gradually decreased. These data suggested that the cells treated with 5-FU for more than 144 h were still in the S-phase with or without DNA synthesis.

CONCLUSIONS

In head and neck carcinoma cells, we showed 5-FU pretreatment enhanced cisplatin cytotoxicity. The result of cell cycle analysis and immunostaining showed S-phase arrest by treatment of prolonged 5-FU treatment. The very long arrest in S-phase might be a mechanism to enhance cisplatin cytotoxicity by 5-FU pretreatment. We thus suggest pretreatment with 5-FU to enhance the effectiveness of cisplatin-based chemotherapy.

FANCD2 depletion sensitizes cancer cells repopulation ability in vitro

Inactivation of Fanconi anemia/BRCA pathway in some cancers causes increased sensitivity to various drugs used for chemo-therapy. Several approaches have been suggested to artificially disrupt this pathway for better treatment. In our study, we have utilized RNA interference technique to knock-down the expression of FANCD2 and sensitize cancer cells undergoing treatment with DNA damaging agents. For this purpose, we transiently depleted FANCD2 by siRNA in a number of breast, bladder, or liver cancer cell lines and screened for mitomycin C or gamma-irradiation sensitivity changes. We could show that knocking-down FANCD2 gene expression increases sensitivity of cancer cells to mitomycin C and to less extent to gamma-rays. Importantly, this effect strongly correlates to repopulation ability of cancer cells and those cell lines with significant FANCD2 depletion revealed decreased recurrence capacity. In summary, the results we presented show proof of principle that opens new possibilities for further preclinical trials.

Modified radical neck dissection and minimal invasive tumor surgery in the middle of split course of concomitant chemoradiotherapy of advanced HNSCC

OBJECTIVE

The effectiveness of modified radical neck dissection with concomitant chemoradiotherapy in patients with N2/3 advanced head and neck cancer was evaluated.

STUDY DESIGN AND SETTING

Retrospective study of 35 patients treated at the University Hospital, Medical University, Innsbruck. The treatment consisted of a split course radiation up to 70 Gy with concomitant chemotherapy with Mytomicin C and 5-fluorouracil. Neck dissection and/or tumor resection was performed between the two cycles of radiation and chemotherapy.

RESULTS

The 2-year progression-free survival was 64%, locoregional control 92% and overall survival 55. Observed toxicities included mucositis (grade 3, 35%; grade 4, 16%), neutropenia (grade 4, 28%), and thrombocytopenia (grade 4, 26%). No complications related to modified radical neck dissection were observed.

CONCLUSION

Intermittent neck dissection was highly effective in controlling the neck disease. Mitomycin C-based chemoradiotherapy for treatment of locally advanced cancer seems to be an option to cisplatin-based regimens.