Risk factors and etiology of surgical site infection after radical neck dissection in patients with head and neck cancer

Surgical Site Infection after Primary Open Surgery for Laryngeal Cancer in a Tertiary Hospital in Belgrade, Serbia: A 10-Year Prospective Cohort Study

BACKGROUND

Surgical site infection (SSI) in laryngeal cancer (LC) patients significantly increases morbidity and may postpone adjuvant therapy. Additionally, SSI can prolong hospitalization, thus representing a burden for the healthcare system. Most of the published studies refer to SSI after salvage laryngectomy.

METHODS

The present prospective cohort study aimed to clarify the incidence and factors associated with SSI in patients after primary open surgery for LC. Through regular hospital surveillance of patients who underwent primary partial or total laryngectomy, we gathered 24 putative factors and identified SSI from 2013 to 2022. Patients with SSI were compared with patients without SSI.

RESULTS

SSI was observed in 21 (6.6%) of 319 patients. ULRA showed that the occurrence of SSI was significantly associated with the American Society of Anesthesiologists (ASA) score, other postoperative healthcare-associated (HAI) infection, T classification, N classification, advanced clinical stage (III-IV), length of stay (LOS), duration of drainage, and the National Healthcare Safety Network (NHSN) risk index. Multivariate logistic regression analysis identified two independent factors associated with SSI occurring in these patients: duration of drainage (RR (relative risk) 1.593; 95% CI 1.159-2.189; p = 0.004) and LOS (RR: 1.074; 95% CI: 1.037-1.112; p < 0.001).

CONCLUSIONS

Our study provided insight into the burden of SSI in LC patients, highlighting several priority areas and targets for quality improvement.

Impact of dental state and surgical factors on postoperative neck infection in oral cancer patients

Postoperative neck infection (PONI) is a known complication of neck dissection. In this study we explored the impact of dental status on the development of PONI, using orthopantomograms to assess edentulism, periodontal health, and caries status. Retrospective analysis was performed for all new oral cancer patients who had neck dissection between January 2008 and January 2020 in a tertiary head and neck centre. PONI risk factors assessed included patient characteristics, dental status, tumour, and surgical factors. Development of PONI was the primary outcome. Edentulous patients had lower risk of PONI (OR 0.06, p = 0.026) compared to those with 21 or more teeth. Periodontitis and dental caries were not statistically significant. Current smokers (OR 2.09, p = 0.044) and free flap reconstruction (OR 5.41, p < 0.001) were also significant predictors for development of PONI. This study highlights the presence of teeth as a potential source of infection post neck dissection and that orthopantomogram assessment may be inadequate to identify at risk patients. Future studies are required on direct clinical assessment of dentition to evaluate the impact of dental optimisation in prevention of PONI.

Incidence and risk factors of surgical site infection in patients with head and neck cancer: A meta-analysis

We systematically review the incidence and risk factors of surgical site infection (SSI) in patients with head and neck cancer. PubMed, Embase, Cochrane Library, and Web of Science databases were searched to obtain studies on the risk factors for SSI in patients with HNC. The retrieval time was from the establishment of the database to February 2023. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias in included studies. Meta-analysis was performed by using Stata 15.1 software. A total of 32 articles including 128 919 patients with head and neck cancer and 2949 cases of SSI were included in this meta-analysis. The incidence rate of SSI in head and neck cancer ranges from 19% to 29%, and the overall infection rate was 24%. Meta-analysis indicated that BMI < 20 kg/m2 (OR, 2.64; 95% CI, 1.74-4.00; I2 , 0%), diabetes (OR, 3.00; 95% CI, 2.12-4.16; I2 , 60.6%), ASA score (OR, 1.51; 95% CI, 1.29-1.77; I2 , 0%), radiotherapy (OR, 2.27; 95% CI, 1.87-2.77; I2 , 44.8%), chemotherapy (OR, 2.36; 95% CI, 1.64-3.40; I2 , 0%), clindamycin antibiotic (OR, 2.99; 95% CI, 1.82-2.93; I2 , 36.5%), deficit repair (OR, 3.76; 95% CI, 1.22-11.59; I2 , 91.4%), neck dissection (OR, 2.13; 95% CI, 1.63-2.79; I2 , 16.4%), blood transfusion (OR, 2.29; 95% CI, 1.52-3.45; I2 , 66.2%), mandibular (OR, 3.17; 95% CI, 1.85-5.42; I2 , 73%), tracheostomy (OR, 2.51; 95% CI, 1.74-3.62; I2 , 86.4%), operation time (OR, 1.42; 95% CI, 1.16-1.74; I2 , 86.4%), ALB (OR, 2.48; 95% CI, 1.95-3.15; I2 , 5.3%) were risk factors of surgical site infection in patients with head and neck cancer (p < 0.05). The results of the sensitivity analysis showed good agreement in all risk factors and the results had stability. The present meta-analysis suggests that BMI < 20 kg/m2 , diabetes, ASA score, radiotherapy, chemotherapy, clindamycin antibiotic, deficit repair, neck dissection, blood transfusion, mandibular, tracheostomy, operation time, and ALB were significant risk factors for SSI.

Mapping the Risk Factors of Pharyngocutaneous Fistula After Salvage Laryngectomies

To evaluate the postoperative surgical wound infection prevalence rates of patients undergoing SL, identify the causative organism and determine predisposing factors leading to infection. A retrospective study of all consecutive patients who underwent salvage total laryngectomy at our unit between 2015 and 2020 was performed. The following parameters were also analyzed: age, smoking history, pre and postoperative albumin level, history of radio and chemo-radiotherapy, reconstruction with pectoralis flap, intraoperative tracheoesophageal puncture, and tumor stage. A total of 12 of the 21 patients (57%) experienced a postoperative infection after SL during the study period. 82% of those patients whose preoperative albumin level below 3gm/dl developed postoperative infection. There is a significant increase (p < 0.01) in infection in patients with N1 and 2 stage tumor (68%) compared with the N0 stage tumors (40%). Multivariate analysis showed that preoperative albumin and nodal stage were significant risk factors for postoperative infection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-021-02603-y.

Post-Operative Infections in Head and Neck Cancer Surgery: Risk Factors for Different Infection Sites

Background: Post-operative infections in head and neck cancer (HNC) surgery represent a major problem and are associated with an important increase in mortality, morbidity, and burden on the healthcare system. The aim of this retrospective observational study was to evaluate post-operative infections in HNC surgery and to analyze risk factors, with a specific focus on different sites of infection. Methods: Clinical data about 488 HNC patients who underwent surgery were recorded. Univariate and multivariate analyses were performed to identify risk factors for post-operative infections. Results: Post-operative infections were observed in 22.7% of cases. Respiratory and surgical site infections were the most common. Multiple site infections were observed in 3.9% of cases. Considering all infection sites, advanced stage, tracheotomy, and higher duration of surgery were risk factors at multivariate analysis. Median hospital stay was significantly longer in patients who had post-operative infection (38 vs. 9 days). Conclusions: Post-operative infections may negatively affect surgical outcomes. A correct identification of risk factors may help the physicians to prevent post-operative infections in HNC surgery.

Osteocutaneous-flap-related osteomyelitis following mandibular reconstruction: a cohort study of an emerging and complex bone infection

Abstract. Osteocutaneous flap (OCF) mandible reconstruction is at high risk for surgical site infection. This study aimed to describe diagnosis, management, and outcome of OCF-related osteomyelitis. All patients managed at our institution for an OCF-related osteomyelitis following mandible reconstruction were included in a retrospective cohort study (2012–2019). Microbiology was described according to gold-standard surgical samples, considering all virulent pathogens, and potential contaminants if present on at least two samples. Determinants of treatment failure were assessed by logistic regression and Kaplan–Meier curve analysis. The 48 included patients (median age 60.5 (IQR, 52.4–66.6) years) benefited from OCF mandible reconstruction mostly for carcinoma (n=27/48; 56.3 %) or osteoradionecrosis (n=12/48; 25.0 %). OCF-related osteomyelitis was mostly early (≤3 months post-surgery; n=43/48; 89.6 %), presenting with local inflammation (n=28/47; 59.6 %), nonunion (wound dehiscence) or sinus tract (n=28/47; 59.6 %), and/or bone or device exposure (n=21/47; 44.7 %). Main implicated pathogens were Enterobacteriaceae (n=25/41; 61.0 %), streptococci (n=22/41; 53.7 %), Staphylococcus aureus (n=10/41; 24.4 %), enterococci (n=9/41; 22.0 %), non-fermenting Gram-negative bacilli (n=8/41; 19.5 %), and anaerobes (n=8/41; 19.5 %). Thirty-nine patients (81.3 %) benefited from surgery, consisting of debridement with implant retention (DAIR) in 25/39 (64.1 %) cases, associated with 93 (IQR, 64–128) days of antimicrobial therapy. After a follow-up of 18 (IQR, 11–31) months, 24/48 (50.0 %) treatment failures were observed. Determinants of treatment outcomes were DAIR (OR, 3.333; 95 % CI, 1.020–10.898) and an early infectious disease specialist referral (OR, 0.236 if ≤2 weeks; 95 % CI, 0.062–0.933). OCF-related osteomyelitis following mandibular reconstruction represents difficult-to-treat infections. Our results advocate for a multidisciplinary management, including an early infectious-disease-specialist referral to manage the antimicrobial therapy driven by complex microbiological documentation.

Antibiotic resistance in the patient with cancer: Escalating challenges and paths forward

Infection is the second leading cause of death in patients with cancer. Loss of efficacy in antibiotics due to antibiotic resistance in bacteria is an urgent threat against the continuing success of cancer therapy. In this review, the authors focus on recent updates on the impact of antibiotic resistance in the cancer setting, particularly on the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). This review highlights the health and financial impact of antibiotic resistance in patients with cancer. Furthermore, the authors recommend measures to control the emergence of antibiotic resistance, highlighting the risk factors associated with cancer care. A lack of data in the etiology of infections, specifically in oncology patients in United States, is identified as a concern, and the authors advocate for a centralized and specialized surveillance system for patients with cancer to predict and prevent the emergence of antibiotic resistance. Finding better ways to predict, prevent, and treat antibiotic-resistant infections will have a major positive impact on the care of those with cancer.

The Utility of Comorbidity Indices in Assessing Head and Neck Surgery Outcomes: A Systematic Review

OBJECTIVE

To evaluate the utility of comorbidity index (CI) scores in predicting outcomes in head and neck surgery (HNS). The CIs evaluated were the Charlson Comorbidity Index (CCI), Elixhauser Comorbidity Index (ECI), Kaplan-Feinstein Index (KFI), American Society of Anesthesiologists Physical Status (ASA-PS), Adult Comorbidity Evaluation-27 (ACE-27), National Cancer Institute Comorbidity Index (NCI-CI), and the Washington University Head and Neck Comorbidity Index (WUHNCI).

METHODS

We report a systematic review according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic databases (PubMed, Cochrane, and Embase) and manual search of bibliographies identified manuscripts addressing how CI scores related to HNS outcomes.

RESULTS

A total of 116 studies associated CI scores with HNS outcomes. CIs were represented in the literature as follows: ASA-PS (70/116), CCI (39/116), ACE-27 (24/116), KFI (7/116), NCI-CI (3/116), ECI (2/116), and WUHNCI (1/116). The most frequently cited justification for calculating each CI (if provided) was: CCI for its validation in other studies, ACE-27 for its utility in cancer patients, and ECI for its comprehensive design. In general, the CCI and ACE-27 were predictive of mortality in HNS. The ECI was most consistent in predicting >1-year mortality. The ACE-27 and KFI were most consistent in predicting medical complications.

CONCLUSION

Despite inconsistencies in the literature, CIs provide insights into the impact of comorbidities on outcomes in HNS. These scores should be employed as an adjunct in the preoperative assessment of HNS patients. Comparative studies are needed to identify indices that are most reliable in predicting HNS outcomes.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

LigaSure small jaw versus conventional neck dissection: a systematic review and meta-analysis

Background

Neck dissection has a central role in the management of head and neck cancers. This systematic review aimed to compare the intraoperative and postoperative parameters between conventional and LigaSure Small Jaw (LSJ)-assisted neck dissection.

Methods

PubMed (MEDLINE), Embase, and the Cochrane Library were searched.

independently by two authors for relevant articles comparing the outcomes of conventional and LSJ-assisted neck dissection. Data from each study were extracted, and a random-effects model was used in the pooled analysis.

Results

Compared with conventional techniques, LSJ-assisted neck dissection was associated with a significantly reduced operative time. The rates of postoperative hematoma, infection, amount of intraoperative blood loss, the length of hospital stay and the drainage amount showed no significant intergroup differences.

Conclusions

The meta-analysis provides evidence that properly using LSJ may reduce the operative time compared with that of conventional techniques. Surgeons may consider using LSJ in neck dissection according to personal experiences.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40463-021-00504-2.

Surgical Site Infection in Head and Neck Surgery: A National Perspective

OBJECTIVES

To examine trend, prevalence, and outcomes of surgical site infection (SSI) in head and neck surgery.

STUDY DESIGN

Retrospective cross-sectional analysis.

SETTING

The Nationwide Readmissions Database (2010-2014), which represents 56.6% of all US hospitalization.

SUBJECTS

Adult patients (≥18 years) who underwent head and neck surgery. Patients with SSI were compared with controls.

METHODS

Analysis included chi-square test and multivariate logistic and linear regression models.

RESULTS

A total of 427 cases and 116,921 controls were identified. SSI prevalence among patients who underwent head and neck surgery was 0.37%, of which 41.0% was reported within the initial admission while the remaining 59.0% was reported on readmission within 30 days of first surgery. SSI was associated with a higher mortality risk (odds ratio, 3.95; 95% CI, 1.25-12.50; P = .019). Multivariate analysis demonstrated that a higher risk of SSI was associated with major surgery of the ear, nose and paranasal sinuses, mouth and tonsil, salivary glands and ducts, maxillofacial bones and mandible, and pharynx and larynx (P < .05 each). However, a lower risk of SSI was reported in thyroid and parathyroid and nonmajor procedures (P < .05 each). Other factors associated with a higher risk of SSI included multiple comorbidities, smoking, cancer diagnosis, concomitant neck dissection, and tracheostomy (P < .05 each). SSI was associated with a mean ± SE additional hospital stay of 8.1 ± 0.8 days per case (P < .001) and an additional cost on the health system of $20,953.00 ± $186.3 per case (P < .001).

CONCLUSIONS

SSI is associated with a significant mortality risk and burden on the health system. More than half of SSI cases were identified on readmission.

A Nested Case-Control Study on the Risk of Surgical Site Infection After Thyroid Surgery

Introduction

It is unclear if antibiotic prophylaxis reduces the risk of surgical site infection (SSI) in thyroid surgery. This study assessed risk factors for SSI and antibiotic prophylaxis in subgroups of patients.

Method and design

A nested case–control study on patients registered in the Swedish National Register for Endocrine Surgery was performed. Patients with SSI were matched 1:1 by age and gender to controls. Additional information on patients with SSI and controls was queried from attending surgeons using a questionnaire. Risk factors for SSI were evaluated by logistic regression analysis and presented as odds ratio (OR) with 95% confidence interval (CI).

Results

There were 9494 operations; 109 (1.2%) patients had SSI. Patients with SSI were older (median 53 vs. 49 years) than patients without SSI p = 0.01 and more often had a cancer diagnosis 23 (21.1%) versus 1137 (12.1%) p = 0.01. In the analysis of patients with SSI versus controls, patients with SSI more often had post-operative drainage 68 (62.4%) versus 46 (42.2%) p = 0.01 and lymph node surgery 40 (36.7%) versus 14 (13.0%) p < 0.01, and both were independent risk factors for SSI, drain OR 1.82 (CI 1.04–3.18) and lymph node dissection, OR 3.22 (95% CI 1.32–7.82). A higher number of 26(62%) patients with independent risk factors for SSI and diagnosed with SSI did not receive antibiotic prophylaxis. Data were missing for 8 (31%) patients.

Conclusion

Lymph node dissection and drain are independent risk factors for SSI after thyroidectomy. Antibiotic prophylaxis might be considered in patients with these risk factors.

Female radical cystectomy patients have a higher risk of surgical site infections

INTRODUCTION

Surgical site infections (SSI) are common after radical cystectomy. The objectives of this study were to evaluate if female sex is associated with postoperative SSI and if experiencing an SSI was associated with subsequent adverse events.

METHODS

This was a historical cohort study of radical cystectomy patients from the American College of Surgeons' National Surgical Quality Improvement Program database between 2006 and 2016. The primary outcome was development of a SSI (superficial, deep, or organ/abdominal space) within 30 days of surgery. Multivariable logistic regression analyses were performed to determine the association between sex and other patient/procedural factors with SSI. Female patients with SSI were also compared to those without SSI to determine risk of subsequent adverse events.

RESULTS

A total of 9,275 radical cystectomy patients met the inclusion criteria. SSI occurred in 1,277(13.7%) patients, 308 (16.4%) females and 969 (13.1%) males (odds ratio = 1.27; 95% confidence interval 1.10-1.47; P = 0.009). Infections were superficial in 150 (8.0%) females versus 410 (5.5%) males (P < 0.0001), deep in 40 (2.1%) females versus 114 (1.5%) males (P = 0.07), and organ/abdominal space in 118 (6.2%) females versus 445 (6.0%) males (P = 0.66). On multivariable analysis, female sex was independently associated with SSI (odds ratio = 1.21 confidence interval 1.01-1.43 P = 0.03). Females who experience SSI had higher probability of developing other complications including wound dehiscence, septic shock, and need for reoperation (all P < 0.05).

CONCLUSIONS

Female sex is an independent risk factor for SSI following radical cystectomy. More detailed study of patient factors, pathogenic microbes, and treatment factors are needed to prescribe the best measures for infection prophylaxis.

Infectious complications in head and neck surgery: Porto Oncology Centre retrospective analysis

OBJECTIVE

To analyze the impact of infectious complications and microbiology in the postoperative period after major oncologic neck surgeries.

METHODS

A retrospective study conducted in an oncology center, including all the consecutive patients who developed infectious complications after major neck cancer surgery, from October 2012 to May 2016 (44 months). Among other data, we collected TNM stage, ASA score, body mass index, comorbidities and habits, pre and postoperative hemoglobin levels, albumin serum levels, pre-surgical treatments, length of inpatient stay, isolated microbiological agents and the recorded complications and mortality rate.

RESULTS

In the studied period, 761 major neck surgeries were performed. Of these, 96 patients had complications (12.6%). Pharyngocutaneous fistula (PCF) was the most frequent complication (56%) and nosocomial pneumonia was the most common systemic complication (23%). Pseudomonas aeruginosa was the principal microorganism of the 26 species isolated (15%). 12 deaths were registered. Using multiple linear regression we concluded that flap/cutaneous necrosis and PCF were complications with statistical significance that prolonged inpatient stay. The same complications had significant relative risk for more than 30 days of hospitalization.

CONCLUSION

The postoperative period is critical for the successful treatment of head and neck oncology patients. PCF and flap/cutaneous necrosis were the principal complications which worsened the outcomes during this critical period. The early recognition and treatment of these complications is crucial.

Nutritional and hematologic markers as predictors of risk of surgical site infection in patients with head and neck cancer undergoing major oncologic surgery

BACKGROUND

Surgical site infection is a complication of surgery for patients with head and neck cancer. We examined the risk factors for surgical site infection in patients undergoing surgery for head and neck cancer.

METHODS

The study involved 369 patients who underwent surgery for head and neck cancer. Hematological and nutritional parameters were measured preoperatively and postoperatively. Univariate and multivariate analyses were used to determine the risk factors for surgical site infection.

RESULTS

Of the 369 patients, 104 (28.2%) had surgical site infections: 45 (12.2%) superficial incisional; 6 (1.6%) deep incisional; and 53 (14.4%) organ/space infections. Multivariate analyses showed that history of radiotherapy, weight loss at diagnosis (>5%), preoperative hypoalbuminemia, neutrophil/lymphocyte ratio (NLR), reconstructive surgery, and tracheostomy were the independent factors predictive of surgical site infection. Patients with preoperative low serum albumin levels (<3.3 g/L) had a 3-fold higher risk of surgical site infection.

CONCLUSION

Our study shows that patient nutritional and hematological markers are associated with the risk of surgical site infection after major surgery for head and neck cancer.

Considerations for antibiotic prophylaxis in head and neck cancer surgery

Peri/post-operative antibiotic prophylaxis (POABP) has become standard practice for preventing surgical site infections (SSI) in head and neck cancer patients undergoing microvascular reconstruction, but few data exist on optimal POABP regimens. Current surgical prophylaxis guideline recommendations fail to account for the complexity of microvascular reconstruction relative to other head and neck procedures, specifically regarding wound classification and antibiotic duration. Selection of POABP spectrum is also controversial, and must balance the choice between too narrow, risking subsequent infection, or too broad, and possible unwanted effects (e.g. antibiotic resistance, Clostridium difficile-associated diarrhea). POABP regimens should retain activity against bacteria expected to colonize the upper respiratory/salivary tracts, which include Gram-positive organisms and facultative anaerobes. However, Gram-negative bacilli also contribute to SSI in this setting. POABP doses should be optimized in order to achieve therapeutic tissue concentrations at the surgical site. Antibiotics targeted towards methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa are not warranted for all patients. Prolonged POABP durations have shown no differences in SSI when compared to short POABP durations, but prolonged durations provide unnecessarily antibiotic exposure and risk for adverse effects. Given the lack of standardization behind antibiotic POABP in this setting and the potential for poor patient outcomes, this practice necessitates an additional focus of surgeons and antimicrobial stewardship programs. The purpose of this review is to provide an overview of POABP evidence and discuss pertinent clinical implications of appropriate use.

Post-operative MRSA infections in head and neck surgery

PURPOSE

Surgical site infection (SSI) with methicillin-resistant Staphylococcus aureus (MRSA) is a serious post-operative complication, with head and neck cancer patients at greater risk due to the nature of their disease. Infection with MRSA has been shown to be costly and impart worse outcomes on patients who are affected. This study investigates incidence and risks for MRSA SSIs at a tertiary medical institution.

MATERIALS AND METHODS

This study reviewed 577 head and neck procedures from 2008 to 2013. Twenty-one variables (i.e. tumor characteristics, patient demographics, operative course, cultures) were analyzed with SPSS to identify trends. A multivariate analysis controlled for confounders (age, BMI, ASA class, length of stay) was completed.

RESULTS

We identified 113 SSIs of 577 procedures, 24 (21.23%) of which were MRSA. Of all analyzed variables, hospital exposure within the preceding year was a significant risk factor for MRSA SSI development (OR 2.665, 95% CI: 1.06-6.69, z statistic 2.086, p=0.0369). Immunosuppressed patients were more prone to MRSA infections (OR 14.1250, 95%CI: 3.8133-52.3217, p<0.001), and patients with a history of chemotherapy (OR 3.0268, 95% CI: 1.1750-7.7968, p=0.0218). Furthermore, MRSA SSI resulted in extended post-operative hospital stays (20.8±4.72days, p=0.031).

CONCLUSIONS

Patients who have a history of chemotherapy, immunosuppression, or recent hospital exposure prior to their surgery are at higher risk of developing MRSA-specific SSI and may benefit from prophylactic antibiotic therapy with appropriate coverage. Additionally, patients who develop MRSA SSIs are likely to have an extended postoperative inpatient stay.

The oral cavity microbiota: between health, oral disease, and cancers of the aerodigestive tract

Many studies show that the human microbiome plays a critical role in the chronic pathologies of obesity, inflammatory bowel diseases, and diabetes. More recently, the interaction between cancer and the microbiome has been highlighted. Most studies have focused on the gut microbiota because it represents the most extensive bacterial community, and the body of evidence correlating it with gut syndromes is increasing. However, in the strict sense, the gastrointestinal (GI) tract begins in the oral cavity, and special attention should be paid to the specific flora of this cavity. This study reviewed the current knowledge about the various microbial ecosystems of the upper part of the GI tract and discussed their potential link to carcinogenesis. The overall composition of the microbial communities, as well as the presence or absence of "key species", in relation to carcinogenesis is addressed. Alterations in the oral microbiota can potentially be used to predict the risk of cancer. Molecular advances and the further monitoring of the microbiota will increase our understanding of the role of the microbiota in carcinogenesis and open new perspectives for future therapeutic and prophylactic modalities.