Complete and durable regression of leptomeningeal involvement during lorlatinib treatment in a patient with lung cancer.

Metastatic spread to the central nervous system (CNS) is frequent in anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) and has an important impact on patient prognosis and quality of life. Leptomeningeal involvement may occur in up to 10% of cases of ALK-positive NSCLC. Lorlatinib is a third-generation ALK inhibitor that has excellent CNS penetrability and demonstrated its efficacy both in pretreated and treatment-naive patients. Herein, we present the case of a 34-year-old patient diagnosed with stage IV ALK-rearranged NSCLC who received two lines of ALK inhibitors (crizotinib followed by alectinib) and several courses of brain stereotactic ablative radiotherapy until leptomeningeal involvement was detected. Third-line lorlatinib was then administered, and 2 months later encephalic MRI documented complete regression of the leptomeningeal involvement that is still maintained after 36 months while treatment with lorlatinib is still ongoing with good tolerability. To the best of our knowledge, this is the longer intracranial response reported in the literature, underlining the importance of the most appropriate choice of systemic treatments and their integration with loco-regional approaches to improve outcomes.

Oligorecurrent Non-Small-Cell Lung Cancer Treated by Chemo-Radiation Followed by Immunotherapy and Intracranial Radiosurgery: A Case Report and Mini Review of Literature.

Locally advanced non-small-cell lung cancer still represents a "grey zone" in terms of the best treatment choice and optimal clinical outcomes. Indeed, most patients may be suitable to receive different treatments with similar outcomes such as chemo-radiotherapy (CHT-RT) followed by immunotherapy (IO) or surgery followed by adjuvant local/systemic therapies. We report a clinical case of a patient submitted to primary thoracic surgery who developed a mediastinal nodal recurrence successfully treated by CHT-RT-IO. Subsequently, a single brain lesion was found to have been successfully treated by single fraction stereotactic ablative radiotherapy. The patient is still on follow-up and she is free from disease having a good quality of life. In this report, we also perform a mini review about the role of CHT-RT followed by IO in treating loco-regional relapse after surgery. The role of SABR after IO is also evaluated, finding that it is safe and well tolerated. More robust and larger clinical data are needed in this particular setting to better define the role of the combination of systemic and local treatments in the management of intrathoracic and intracranial relapse for patients already submitted to CHT-RT followed by immunotherapy.

Evaluating the impact of chemotherapy-induced nausea and vomiting on daily functioning in patients receiving dexamethasone-sparing antiemetic regimens with NEPA (netupitant/palonosetron) in the cisplatin setting: results from a randomized phase 3 study.

BACKGROUND: The non-inferiority of dexamethasone (DEX) on day 1, with or without low-dose DEX on days 2 and 3, combined with oral NEPA (netupitant/palonosetron), compared with the guideline-consistent use of DEX was demonstrated in cisplatin. Here, we complete the analysis by assessing the impact of emesis on daily lives of patients receiving DEX-sparing regimens using the Functional Living Index-Emesis (FLIE). METHODS: Chemotherapy-naïve patients undergoing cisplatin (≥70 mg/m2), were given NEPA and DEX (12 mg) on day 1 and randomized to receive either 1) no further DEX (DEX1), 2) oral DEX (4 mg daily) on days 2-3 (DEX3), or 3) DEX (4 mg twice daily) on days 2-4 (DEX4; control). Patients completed the FLIE questionnaire on day 6 of cycle 1. Endpoints included the FLIE nausea domain, vomiting domain, and overall combined domain scores, as well as the proportion of patients with no impact on daily life (NIDL; overall score > 108). This was a protocol-planned analysis. RESULTS: In the DEX1 group, no significant differences were observed in the FLIE nausea score (48.9 [±1.8; SE] vs. 53.7 [±1.5]), vomiting score (56.6 [±1.4] vs. 58.7 [±0.8]) and overall score (105.6 [±2.8] vs.112.4 [±1.9]) versus DEX4 control; similar results were observed in the DEX3 group for nausea score (49.6 [±1.7]), vomiting score (58.2 [±1]) and overall score (107.8 [±2.4]) versus control. There were no significant between-group differences in the proportion of patients reporting NIDL. CONCLUSION: Reducing DEX, when administered with NEPA, does not seem to adversely impact the daily functioning in patients undergoing cisplatin. TRIAL REGISTRATION: ClinicalTrials.gov NCT04201769 . Registration date: 17/12/2019 - Retrospectively registered.

Dissecting Immunotherapy Strategies for Small Cell Lung Cancer: Antibodies, Ionizing Radiation and CAR-T.

Small cell lung cancer (SCLC) is a highly aggressive malignancy that accounts for about 14% of all lung cancers. Platinum-based chemotherapy has been the only available treatment for a long time, until the introduction of immune checkpoint inhibitors (ICIs) recently changed first-line standard of care and shed light on the pivotal role of the immune system. Despite improved survival in a subset of patients, a lot of them still do not benefit from first-line chemo-immunotherapy, and several studies are investigating whether different combination strategies (with both systemic and local treatments, such as radiotherapy) may improve patient outcomes. Moreover, research of biomarkers that may be used to predict patients' outcomes is ongoing. In addition to ICIs, immunotherapy offers other different strategies, including naked monoclonal antibodies targeting tumor associated antigens, conjugated antibody, bispecific antibodies and cellular therapies. In this review, we summarize the main evidence available about the use of immunotherapy in SCLC, the rationale behind combination strategies and the studies that are currently ongoing in this setting, in order to give the reader a clear and complete view of this rapidly expanding topic.

Dexamethasone-Sparing Regimens with Oral Netupitant and Palonosetron for the Prevention of Emesis Caused by High-Dose Cisplatin: A Randomized Noninferiority Study.

BACKGROUND: To reduce the overall exposure to dexamethasone (DEX) in patients receiving cisplatin-based chemotherapy, we evaluated the noninferiority of DEX on day 1, with or without low-dose DEX on days 2 and 3, combined with an oral fixed-dose combination of netupitant and palonosetron (NEPA), compared with the guideline-consistent use of 4-day DEX. PATIENTS AND METHODS: In this open-label, multicenter study, chemotherapy-naïve patients undergoing high-dose cisplatin (≥70 mg/m2 ), were given NEPA and DEX (12 mg) on day 1 and randomized (1:1:1 ratio) to receive either (a) no further DEX (DEX1), (b) oral DEX (4 mg daily) on days 2-3 (DEX3), or (c) DEX (4 mg twice daily) on days 2-4 (DEX4). The primary efficacy endpoint was complete response (CR: no emesis and no rescue medication) during the 5-day overall phase. The noninferiority margin was set at -15% difference (DEX1 or DEX3 minus DEX4). Secondary efficacy endpoints included complete protection (CP: CR and none or mild nausea). RESULTS: Two-hundred twenty-eight patients, 76 in each arm, were assessable. Noninferiority was met for both DEX-sparing regimens and the reference arm, with overall phase CR rates of 76.3% in each of the DEX1 and DEX3 arms and 75.0% in the DEX4 arm (95% confidence interval, -12.3% to 15% for each comparison). During the overall phase, CP rates were similar between groups. CONCLUSION: A simplified regimen of NEPA plus single-dose DEX offers comparable chemotherapy-induced nausea and vomiting prevention throughout 5 days post-chemotherapy with the advantage of sparing patients additional doses of DEX in the high-emetic-risk setting of cisplatin-based chemotherapy. IMPLICATIONS FOR PRACTICE: Dexamethasone (DEX) has traditionally played an integral role in the management of chemotherapy-induced emesis. Although generally considered safe, even short-term DEX use is associated with various side effects, and some evidence suggests that concurrent steroids may reduce the efficacy of immunotherapies. This study demonstrates comparable antiemetic control during the 5 days post-chemotherapy with a simplified regimen of netupitant/palonosetron plus single-dose DEX versus the standard 4-day DEX reference treatment in high-dose cisplatin. This represents a clinically relevant achievement as it not only simplifies antiemetic prophylaxis but also offers an opportunity to appropriately use in patients where caution with corticosteroid use is advised.

Second primary tumors in head and neck cancer patients: The importance of a "tailored" surveillance.

OBJECTIVE: Head and neck cancer survivors have increased risk of developing second primary tumors compared to overall population. Because second primary represents a major cause of morbidity and mortality in this population, early detection is fundamental. MATERIALS AND METHODS: In this 10-year single-institution study, we investigated the following: incidence, clinical-pathological risk factors, and survival of patients with second primary tumor. We included all patients with diagnosis of squamous cell carcinoma of the head and neck seen at the Modena University Hospital from 2008 to 2018. RESULTS: Among 1,177 patients included, 222 (18.9%) developed second primary tumor; its survival probability at 5 years was 40.6%. Alcohol consumption (p = .0055) and index cancer in oropharynx (p = .0029), supraglottic larynx (p = .0000), glottic larynx (p = .0222) were associated with higher risk of second primary. The most common second primary sites were head and neck district and lung (70, 31.5%, and 67, 30.2%, respectively). Head and neck district were more common in oral cavity (18, 43%) and oropharynx index cancer (20, 31%); lung second primary in hypopharynx (4, 40%), supraglottic larynx (17, 43%), and glottic larynx index cancer (23, 35%). CONCLUSION: Head and neck cancer survivors developing a second primary tumor have dismal prognosis. Tailored surveillance is recommended.

Deepening the Knowledge of ROS1 Rearrangements in Non-Small Cell Lung Cancer: Diagnosis, Treatment, Resistance and Concomitant Alterations.

ROS proto-oncogene 1 (ROS1) rearrangements are reported in about 1-2% of non-squamous non-small-cell lung cancer (NSCLC). After efficacy of crizotinib was demonstrated, identification of ROS1 translocations in advanced disease became fundamental to give patients the chance of specific and effective treatment. Different methods are available for detection of rearrangements, and probably the real prevalence of ROS1 rearrangements is higher than that reported in literature, as our capacity to detect gene rearrangements is improving. In particular, with next generation sequencing (NGS) techniques, we are currently able to assess multiple genes simultaneously with increasing sensitivity. This is leading to overcome the "single oncogenic driver" paradigm, and in the very near future, the co-existence of multiple drivers will probably emerge more frequently and represent a therapeutic issue. Since recently, crizotinib has been the only available therapy, but today, many other tyrosine kinase inhibitors (TKI) are emerging and seem promising both in first and subsequent lines of treatment. Indeed, novel inhibitors are also able to overcome resistance mutations to crizotinib, hypothesizing a possible sequential strategy also in ROS1-rearranged disease. In this review, we will focus on ROS1 rearrangements, dealing with diagnostic aspects, new therapeutic options, resistance issues and the coexistence of ROS1 translocations with other molecular alterations.

Correction to: Which elderly newly diagnosed glioblastoma patients can benefit from radiotherapy and temozolomide? A PERNO prospective study.

The members of the PERNO Study Group were not individually captured in the metadata of the original publication. They are included in the metadata of this publication.

Which elderly newly diagnosed glioblastoma patients can benefit from radiotherapy and temozolomide? A PERNO prospective study.

The role of temozolomide concurrent with and adjuvant to radiotherapy (RT/TMZ) in elderly patients with glioblastoma (GBM) remains unclear. We evaluated the outcome of patients >70 years in the context of the Project of Emilia-Romagna Region in Neuro-Oncology (PERNO), the first Italian prospective observational population-based study in neuro-oncology. For this analysis the criteria for selecting patients enrolled in the PERNO study were: age >70 years; PS 0-3; histologically confirmed GBM; postoperative radiotherapy (RT) after surgery with or without concomitant temozolomide (TMZ) or postsurgical TMZ alone. Between January 2009 and December 2010, 76 GBM elderly patients were identified in the prospective PERNO study. Twenty-three patients did not receive any treatment after surgery, and 53 patients received postsurgical treatments (25 patients received RT alone and 28 patients RT/TMZ). Median survival was 11.1 months (95 % CI 8.8-13.5), adding temozolomide concomitant and adjuvant to radiotherapy it was 11.6 months (95 % CI 8.6-14.6), and 9.3 months (95 % CI 8.1-10.6) in patients treated with RT alone (P = 0.164). However, patients with MGMT methylated treated with RT/TMZ obtained a better survival (17.2 months, 95 % CI 11.5-22.9) (P = 0.042). No difference in terms of survival were observed if patients with MGMT unmethylated tumor received RT alone, or RT/TMZ or, in MGMT methylated tumor, if patients received radiotherapy alone. In elderly patients RT/TMZ represent a widely used approach but it is effective with methylated MGMT tumors only.

Rare Driver Mutations in Advanced, Oncogene-Addicted Non-Small Cell Lung Cancer: A North Italian, Real-World, Registry Experience.

The real-world, retrospective, NEROnE registry investigated the impact of next-generation sequencing (NGS) in advanced non-small-cell lung cancer (NSCLC) patients (pts) at three oncology units in the north of Italy between January 2020 and December 2022. We focused on the clinical characterization and outcomes of NSCLC with rare molecular alterations: EGFR exon 20 insertion, non-activating EGFR mutations, BRAF V600E and non-V600, ROS1 and RET rearrangements, MET, ErbB2, and FGFR mutations. Overall, these represented 6.4% (62/970) of the pts analysed with NGS in the daily practice. The most heavily represented rare alterations were ROS1 rearrangement (15 pts-24%) and MET exon 14 skipping mutation (11 pts-18%). No associations were found with the demographic and clinical features. Forty-nine pts received targeted therapies, of which 38.8% were first- and 9.8% were second-line. The remaining pts received chemotherapy and/or immunotherapy. In terms of the clinical outcomes, although not statistically significant, a tendency toward shorter OS was seen when therapies other than specific targeted therapies were used (HR: 1.84, 95% CI: 0.79-4.33, p = 0.158). The pts with co-mutations (19.4%) seemed to receive an advantage from the front-line chemotherapy-based regimen. Finally, an NLR score (a well-known inflammatory index) ≥ 4 seemed to be related to shorter OS among the pts treated with immunotherapy alone or in combination with chemotherapy (HR: 2.83, 95% CI: 1.08-7.40, p = 0.033). Prospective evaluations need to be performed to clarify whether these indexes may help to identify patients with oncogene-addicted NSCLC who could benefit from immunotherapy.

Essential data variables for a minimum dataset for head and neck cancer trials and clinical research: HNCIG consensus recommendations and database.

The Head and Neck Cancer International Group (HNCIG) has undertaken an international modified Delphi process to reach consensus on the essential data variables to be included in a minimum database for HNC research. Endorsed by 19 research organisations representing 34 countries, these recommendations provide the framework to facilitate and harmonise data collection and sharing for HNC research. These variables have also been incorporated into a ready to use downloadable HNCIG minimum database, available from the HNCIG website.

Real-world outcomes of Italian patients with advanced non-squamous lung cancer treated with first-line pembrolizumab plus platinum-pemetrexed.

PURPOSE: The aim of this multi-center, retrospective/prospective cohort observational study was to evaluate outcomes in routine clinical practice of first-line chemo-immunotherapy with cis/carboplatin, pemetrexed and pembrolizumab in patients with advanced non-squamous non-small cell lung cancer (NSCLC) in 33 Italian centers. METHODS: The outcome measure was to evaluate overall survival (OS) in a real-world patient population. Secondary endpoints were: progression-free survival (PFS), objective response rate (ORR), duration of response (DoR) and incidence of treatment-related adverse events (AEs). RESULTS: 1068 patients were enrolled at the time of data cut-off (January 31st, 2023), and 812 (76.0%) belonged to the retrospective cohort. Median age was 66 years (27-85), ECOG PS was ≥ 2 in 91 (8.6%) patients; 254 (23.8%) patients had brain metastases at baseline; 38 (3.6%) patients had tumor with PD-L1 expression ≥ 50%. After a median follow-up of 17.0 months (95% CI, 16.1-17.9), median OS was 16.1 months (95% CI, 14.4-18.8) and PFS was 9.9 months (95% CI, 8.8-11.2). Median DoR (n = 493) was 14.7 months (95% CI, 13.6-17.1). ORR was 43.4% (95% CI, 40.4-46.4). Any-grade AEs occurred in 636 (59.6%) patients and grade ≥ 3 in 253 (23.7%) patients. Most common grade ≥ 3 AEs were neutropenia (6.3%) and anemia (6.3%). CONCLUSIONS: First-line chemo-immunotherapy was effective and tolerable in this large, real-world Italian study of patients with advanced non-squamous NSCLC. Our results were in line with the KEYNOTE-189 registration study, also considering the low number of PD-L1 ≥ 50% patients included in our study.

APOLLO 11 Project, Consortium in Advanced Lung Cancer Patients Treated With Innovative Therapies: Integration of Real-World Data and Translational Research.

INTRODUCTION: Despite several therapeutic efforts, lung cancer remains a highly lethal disease. Novel therapeutic approaches encompass immune-checkpoint inhibitors, targeted therapeutics and antibody-drug conjugates, with different results. Several studies have been aimed at identifying biomarkers able to predict benefit from these therapies and create a prediction model of response, despite this there is a lack of information to help clinicians in the choice of therapy for lung cancer patients with advanced disease. This is primarily due to the complexity of lung cancer biology, where a single or few biomarkers are not sufficient to provide enough predictive capability to explain biologic differences; other reasons include the paucity of data collected by single studies performed in heterogeneous unmatched cohorts and the methodology of analysis. In fact, classical statistical methods are unable to analyze and integrate the magnitude of information from multiple biological and clinical sources (eg, genomics, transcriptomics, and radiomics). METHODS AND OBJECTIVES: APOLLO11 is an Italian multicentre, observational study involving patients with a diagnosis of advanced lung cancer (NSCLC and SCLC) treated with innovative therapies. Retrospective and prospective collection of multiomic data, such as tissue- (eg, for genomic, transcriptomic analysis) and blood-based biologic material (eg, ctDNA, PBMC), in addition to clinical and radiological data (eg, for radiomic analysis) will be collected. The overall aim of the project is to build a consortium integrating different datasets and a virtual biobank from participating Italian lung cancer centers. To face with the large amount of data provided, AI and ML techniques will be applied will be applied to manage this large dataset in an effort to build an R-Model, integrating retrospective and prospective population-based data. The ultimate goal is to create a tool able to help physicians and patients to make treatment decisions. CONCLUSION: APOLLO11 aims to propose a breakthrough approach in lung cancer research, replacing the old, monocentric viewpoint towards a multicomprehensive, multiomic, multicenter model. Multicenter cancer datasets incorporating common virtual biobank and new methodologic approaches including artificial intelligence, machine learning up to deep learning is the road to the future in oncology launched by this project.

The Prognostic Role of Baseline Eosinophils in HPV-Related Cancers: a Multi-institutional Analysis of Anal SCC and OPC Patients Treated with Radical CT-RT.

BACKGROUND AND AIM: Anal squamous cell carcinoma (SCC) and oropharyngeal cancer (OPC) are rare tumors associated with HPV infection. Bioumoral predictors of response to chemoradiation (CT-RT) are lacking in these settings. With the aim to find new biomarkers, we investigated the role of eosinophils in both HPV-positive anal SCC and HPV-related oropharyngeal cancer (OPC). METHODS: We retrieved clinical and laboratory data of patients with HPV-positive anal SCC treated with CT-RT in 5 institutions, and patients with locally advanced OPC SCC treated with CT-RT in 2 institutions. We examined the association between baseline eosinophil count (the best cutoff has been evaluated by ROC curve analysis: 100 × 10^9/L) and disease-free survival (DFS). Unadjusted and adjusted hazard ratios by baseline characteristics were calculated using the Cox proportional hazards model. RESULTS: Three hundred four patients with HPV-positive anal SCCs and 168 patients with OPCs (122 HPV-positive, 46 HPV-negative diseases) were analyzed. In anal SCC, low eosinophil count (< 100 × 10^9/L) correlates to a better DFS (HR = 0.59; p = 0.0392); likewise, in HPV-positive OPC, low eosinophil count correlates to a better DFS (HR = 0.50; p = 0.0428). In HPV-negative OPC, low eosinophil count confers worse DFS compared to high eosinophil count (HR = 3.53; p = 0.0098). After adjustment for age and sex, eosinophils were confirmed to be independent prognostic factors for DFS (HR = 4.55; p = 0.0139). CONCLUSION: Eosinophil count could be used as a prognostic factor in anal HPV-positive SCC. The worse prognosis showed in HPV-positive patients with high eosinophil count is likely to derive from an unfavorable interaction between the HPV-induced immunomodulation and eosinophils, which may hamper the curative effect of RT.

Oropharyngeal squamous cell carcinoma: Prognostic factors for development of distant metastases and oncological outcomes.

BACKGROUND: Distant metastasis (DM) development in Oropharyngeal Squamous Cell Carcinoma (OPSCC) represents an important prognostic factor. The identification of a phenotype of metastatic patients may better define therapeutic and follow-up programs. METHODS: We included 408 patients with OPSCC, non-metastatic at the time of diagnosis, and treated with curative intent. The Overall Survival (OS) analyses were performed and the impact of developing DM on survival was analyzed through Cox proportional-hazard regression model. RESULTS: 57 (14%) patients develop DM. 302 (74%) were p16+ OPSCC and 35 of them experienced DM. Advanced clinical stage, smoking, p16-status, response to primary treatment, and loco-regional relapse influence the DM rate. Only in the p16+ group, DM onset results in a greater impact on OS (p < 0.0001). Lung metastases have a better OS compared to non-pulmonary ones (p = 0.049). CONCLUSION: This retrospective study shows a possible stratification of OPSCC patients based on the risk of the development of DMs.

Exploratory analysis of the effect of a dexamethasone-sparing regimen for prophylaxis of cisplatin-induced emesis on food intake (LUNG-NEPA study).

We demonstrated the non-inferiority of a dexamethasone (DEX)-sparing (single-dose) regimen with NEPA, a netupitant/palonosetron fixed combination, for preventing chemotherapy-induced nausea and vomiting (CINV) caused by cisplatin. This pre-planned exploratory analysis assessed the effect of the DEX-sparing regimen on a patient's food intake. Chemotherapy-naïve patients undergoing cisplatin (≥ 70 mg/m2) were given NEPA and DEX (12 mg) on day 1 and randomized to receive either no further DEX (DEX1), or oral DEX (4 mg BID) on days 2-4 (DEX4). Patient-reported endpoint maintenance of usual daily food intake was assessed during the 5-days post-chemotherapy. The relationship between usual daily food intake and CINV control, pre-chemotherapy self-rated food intake and BMI-adjusted weight loss (WL) were evaluated. One-hundred fifty-two patients (76/group) were assessable. The proportion of patients reporting maintenance of usual daily food intake was similar in both groups: 69.7% (95% CI, 58.6-78.9) for DEX1 vs. 72.4% (95% CI, 61.4-81.2) for DEX4. Only CINV control was significantly associated with maintenance of usual daily food intake (P ≤ 0.001) during the overall phase. The DEX-sparing regimen does not adversely affect patient-reported daily food intake post-chemotherapy. The current analysis adds further insights into antiemetic efficacy of DEX sparing beyond day 1 in the challenging setting of cisplatin.Trial registration: The parent study was registered on ClinicalTrials.gov (NCT04201769).

A systematic review and meta-analysis on the optimal treatment duration of checkpoint inhibitoRS in solid tumors: The OTHERS study.

No clear evidence supports the advantage of fixed (up to two years (2yICI)) or continuous treatment (more than two years (prolonged ICI)) in cancer patients achieving stable disease or response on immune checkpoint inhibitors (ICIs). We performed a systematic review and meta-analysis of randomized controlled trials reporting the duration of ICIs (alone or in combination with standard of care (SoC)) across various solid tumors. Overall, we identified 28,417 records through database searching. Based on the eligibility criteria, 57 studies were identified for the quantitative synthesis, including 22,977 patients receiving ICIs (with or without SoC). Prolonged ICI correlated with better overall survival (OS) than 2yICI in patients with melanoma (HR:1.55; 95%CI: 1.22,1.98), while 2yICI-SoC led to better OS than prolonged ICI-SoC in patients with NSCLC (HR: 0.84; 95%CI: 0.68,0.89). Prospective randomized trials are needed to assess the most appropriate duration of ICIs. OBJECTIVE: No clear evidence supports the advantage of fixed (up to two years (2yICI)) or continuous treatment (more than two years (prolonged ICI)) in cancer patients achieving stable disease or response on immune checkpoint inhibitors (ICIs). Here, we assessed the optimal treatment duration for ICIs in solid tumors. CONCLUSIONS: Prolonged ICIs administration does not seem to improve the outcomes of patients with NSCLC an RCC.

Dissecting Tumor Growth: The Role of Cancer Stem Cells in Drug Resistance and Recurrence.

Emerging evidence suggests that a small subpopulation of cancer stem cells (CSCs) is responsible for initiation, progression, and metastasis cascade in tumors. CSCs share characteristics with normal stem cells, i.e., self-renewal and differentiation potential, suggesting that they can drive cancer progression. Consequently, targeting CSCs to prevent tumor growth or regrowth might offer a chance to lead the fight against cancer. CSCs create their niche, a specific area within tissue with a unique microenvironment that sustains their vital functions. Interactions between CSCs and their niches play a critical role in regulating CSCs' self-renewal and tumorigenesis. Differences observed in the frequency of CSCs, due to the phenotypic plasticity of many cancer cells, remain a challenge in cancer therapeutics, since CSCs can modulate their transcriptional activities into a more stem-like state to protect themselves from destruction. This plasticity represents an essential step for future therapeutic approaches. Regarding self-renewal, CSCs are modulated by the same molecular pathways found in normal stem cells, such as Wnt/ß-catenin signaling, Notch signaling, and Hedgehog signaling. Another key characteristic of CSCs is their resistance to standard chemotherapy and radiotherapy treatments, due to their capacity to rest in a quiescent state. This review will analyze the primary mechanisms involved in CSC tumorigenesis, with particular attention to the roles of CSCs in tumor progression in benign and malignant diseases; and will examine future perspectives on the identification of new markers to better control tumorigenesis, as well as dissecting the metastasis process.