Mutations in the human epidermal growth factor receptor 2 (HER-2) gene are recognized as significant but relatively rare driver alterations in non-small cell lung cancer (NSCLC). These mutations predominantly manifest as gene mutation, amplification, and protein overexpression, with an estimated prevalence from 2.8% to 15.4% among NSCLC patients in China. Research indicates that HER-2 mutations, particularly exon 20 insertions (ex20ins), are strongly correlated with aggressive tumor biology, poor prognosis, and limited responsiveness to immunotherapy, thereby exhibiting characteristics of "cold tumors". Overexpression and amplification of HER-2 are also indicative of a heightened risk of chemotherapy resistance and unfavorable survival outcomes, suggesting a distinct molecular subtype with unique biological behaviors. In recent years, novel antibody-drug conjugates (ADCs), particularly trastuzumab deruxtecan (T-DXd), have demonstrated groundbreaking efficacy in HER-2-mutant advanced NSCLC patients. These ADCs have shown significant clinical benefits, including high objective response rates and progression-free survival advantages, making T-DXd the first targeted therapy approved for this patient population globally. Additionally, ADCs have exhibited therapeutic potential in patients with HER-2 overexpression, thus broadening the scope of their indications. To standardize the clinical diagnosis and treatment of HER-2 variant NSCLC, the Chinese Anti-cancer Association convened multidisciplinary experts from oncology, pulmonology, thoracic surgery, pathology, and molecular diagnostics to develop this consensus based on the latest evidences from both domestic and international studies, coupled with China's clinical practice experience. This consensus focuses on the molecular characteristics, clinical significance, diagnostic strategies, treatment options, and safety management of HER-2 alterations, addressing ten critical clinical questions in a systematic manner. It is recommended that HER-2 status be routinely tested at initial diagnosis, disease progression, or recurrence in NSCLC. Mutation detection should prioritize next-generation sequencing (NGS), while protein overexpression may be assessed using immunohistochemistry (IHC) standards for gastric cancer. Fluorescence in situ hybridization (FISH) is recommended for detecting HER-2 amplification. Regarding treatment, for HER-2-mutant patients, first-line therapy may involve chemotherapy with or without immune checkpoint inhibitors (ICIs), similar to treatment approaches for driver-gene negative populations. Upon failure of first-line treatment, trastuzumab deruxtecan, may be considered as alternative therapeutic options. For patients with HER-2 overexpression, ADCs should be considered after failure of standard systemic therapy. However, the management of HER-2 amplification remains insufficiently supported by evidence, necessitating a cautious, individualized approach. The consensus also includes detailed recommendations for screening and managing adverse effects associated with ADCs, such as interstitial lung disease (ILD), emphasizing the crucial role of safety management in ensuring treatment efficacy. The publication of this consensus aims to drive the standardization of molecular diagnosis and treatment pathways for HER-2 variant NSCLC, improve clinical outcomes and quality of life for patients, and facilitate the implementation of personalized precision treatment strategies.
Humans ; Carcinoma, Non-Small-Cell Lung/pathology* ; Lung Neoplasms/pathology* ; Receptor, ErbB-2/metabolism* ; Mutation ; Immunoconjugates/therapeutic use* ; Consensus ; Trastuzumab/therapeutic use* ; Camptothecin/analogs & derivatives*

Patients with metastatic castration-resistant prostate cancer (mCRPC) face poor prognoses due to tumor heterogeneity and drug resistance. Antibody-drug conjugates (ADCs) have been under development for over two decades for mCRPC treatment. Several clinical trials have demonstrated promising antitumor activity and acceptable safety profiles for ADCs in this setting. Among prostate-specific membrane antigen (PSMA)-targeted ADCs, ARX517 demonstrates superior safety and more significant prostate-specific antigen (PSA) reductions compared to earlier agents such as MLN2704, PSMA-ADC, and MEDI3726. ADCs targeting B7-H3, such as MGC018 and DB-1311, have also shown antitumor activity. ADCs targeting other antigens, including six-transmembrane epithelial antigen of the prostate (STEAP)1 (DSTP3086S), trophoblast cell surface antigen (TROP)2 (sacituzumab govitecan), and solute carrier (SLC) 44A4 (ASG-5ME), have shown preliminary antitumor activity in early trials but face challenges with insufficient efficacy or toxicity. Tisotumab vedotin (targeting tissue factor) has shown no significant therapeutic response in mCRPC. Meanwhile, disitamab vedotin (HER2-targeted), ABBV-969 and DXC008 (both dual PSMA/STEAP1-targeted) are currently under evaluation. Notably, an international multicenter phase Ⅲ clinical trial (NCT06925737) for mCRPC has been initiated in May 2025 for evaluating B7-H3-targeted ADC ifinatamab deruxtecan. This review summarizes recent advances in ADCs targeting key antigens in mCRPC (including PSMA, B7-H3, STEAP1, TROP2, SLC44A4, and others) and explores combination strategies, offering insights to inform the clinical management of mCRPC.
Humans ; Prostatic Neoplasms, Castration-Resistant/pathology* ; Male ; Immunoconjugates/therapeutic use* ; Glutamate Carboxypeptidase II/immunology* ; Antibodies, Monoclonal, Humanized/therapeutic use* ; B7 Antigens/immunology* ; Neoplasm Metastasis ; Prostate-Specific Antigen ; Antigens, Neoplasm/immunology* ; Antigens, Surface ; Camptothecin/analogs & derivatives* ; Oxidoreductases

Objective: To explore the efficacy of chemotherapy re-challenge in the third-line setting for patients with metastatic colorectal cancer (mCRC) in the real world. Methods: The clinicopathological data, treatment information, recent treatment efficacy, adverse events and survival data of mCRC patients who had disease progression after treatment with oxaliplatin-based and/or irinotecan-based chemotherapy and received third-line chemotherapy re-challenge from January 2013 to December 2020 at Tianjin Medical University Cancer Institute and Hospital were retrospectively collected. Survival curves were plotted with the Kaplan-Meier method, and the Cox proportional hazard model was used to analyze the prognostic factors. Results: A total of 95 mCRC patients were included. Among them, 32 patients (33.7%) received chemotherapy alone and 63 patients (66.3%) received chemotherapy combined with targeted drugs. Eighty-three patients were treated with dual-drug chemotherapy (87.4%), including oxaliplatin re-challenge in 35 patients and irinotecan re-challenge in 48 patients. The remaining 12 patients were treated with triplet chemotherapy regimens (12.6%). Among them, as 5 patients had sequential application of oxaliplatin and irinotecan in front-line treatments, their third-line therapy re-challenged both oxaliplatin and irinotecan; 7 patients only had oxaliplatin prescription before, and these patients re-challenged oxaliplatin in the third-line treatment. The overall response rate (ORR) and disease control rate (DCR) reached 8.6% (8/93) and 61.3% (57/93), respectively. The median progression free survival (mPFS) and median overall survival (mOS) were 4.9 months and 13.0 months, respectively. The most common adverse events were leukopenia (34.7%) and neutropenia (34.7%), followed by gastrointestinal adverse reactions such as nausea (32.6%) and vomiting (31.6%). Grade 3-4 adverse events were mostly hematological toxicity. Cox multivariate analysis showed that gender (HR=1.609, 95% CI: 1.016-2.548) and the PFS of front-line treatments (HR=0.598, 95% CI: 0.378-0.947) were independent prognostic factors. Conclusion: The results suggested that it is safe and effective for mCRC patients to choose third-line chemotherapy re-challenge, especially for patients with a PFS of more than one year in front-line treatments.
Humans ; Irinotecan/therapeutic use* ; Oxaliplatin/therapeutic use* ; Colorectal Neoplasms/pathology* ; Retrospective Studies ; Fluorouracil ; Colonic Neoplasms/chemically induced* ; Rectal Neoplasms/drug therapy* ; Antineoplastic Combined Chemotherapy Protocols/adverse effects* ; Camptothecin/adverse effects*

Objective: To explore the efficacy of chemotherapy re-challenge in the third-line setting for patients with metastatic colorectal cancer (mCRC) in the real world. Methods: The clinicopathological data, treatment information, recent treatment efficacy, adverse events and survival data of mCRC patients who had disease progression after treatment with oxaliplatin-based and/or irinotecan-based chemotherapy and received third-line chemotherapy re-challenge from January 2013 to December 2020 at Tianjin Medical University Cancer Institute and Hospital were retrospectively collected. Survival curves were plotted with the Kaplan-Meier method, and the Cox proportional hazard model was used to analyze the prognostic factors. Results: A total of 95 mCRC patients were included. Among them, 32 patients (33.7%) received chemotherapy alone and 63 patients (66.3%) received chemotherapy combined with targeted drugs. Eighty-three patients were treated with dual-drug chemotherapy (87.4%), including oxaliplatin re-challenge in 35 patients and irinotecan re-challenge in 48 patients. The remaining 12 patients were treated with triplet chemotherapy regimens (12.6%). Among them, as 5 patients had sequential application of oxaliplatin and irinotecan in front-line treatments, their third-line therapy re-challenged both oxaliplatin and irinotecan; 7 patients only had oxaliplatin prescription before, and these patients re-challenged oxaliplatin in the third-line treatment. The overall response rate (ORR) and disease control rate (DCR) reached 8.6% (8/93) and 61.3% (57/93), respectively. The median progression free survival (mPFS) and median overall survival (mOS) were 4.9 months and 13.0 months, respectively. The most common adverse events were leukopenia (34.7%) and neutropenia (34.7%), followed by gastrointestinal adverse reactions such as nausea (32.6%) and vomiting (31.6%). Grade 3-4 adverse events were mostly hematological toxicity. Cox multivariate analysis showed that gender (HR=1.609, 95% CI: 1.016-2.548) and the PFS of front-line treatments (HR=0.598, 95% CI: 0.378-0.947) were independent prognostic factors. Conclusion: The results suggested that it is safe and effective for mCRC patients to choose third-line chemotherapy re-challenge, especially for patients with a PFS of more than one year in front-line treatments.
Humans ; Irinotecan/therapeutic use* ; Oxaliplatin/therapeutic use* ; Colorectal Neoplasms/pathology* ; Retrospective Studies ; Fluorouracil ; Colonic Neoplasms/chemically induced* ; Rectal Neoplasms/drug therapy* ; Antineoplastic Combined Chemotherapy Protocols/adverse effects* ; Camptothecin/adverse effects*

BACKGROUND: The literature recommends that reduced dosage of CPT-11 should be applied in patients with UGT1A1 homozygous mutations, but the impact of UGT1A1 heterozygous mutations on the adverse reactions of CPT-11 is still not fully clear. METHODS: A total of 107 patients with UGT1A1 heterozygous mutation or wild-type, who were treated with CPT-11 from January 2018 to September 2021 in Peking University Third Hospital, were retrospectively enrolled. The adverse reaction spectra of patients with UGT1A1*6 and UGT1A1*28 mutations were analyzed. Adverse reactions were evaluated according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) 5.0. The efficacy was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The genotypes of UGT1A1*6 and UGT1A1*28 were detected by digital fluorescence molecular hybridization. RESULTS: There were 43 patients with UGT1A1*6 heterozygous mutation, 26 patients with UGT1A1*28 heterozygous mutation, 8 patients with UGT1A1*6 and UGT1A1*28 double heterozygous mutations, 61 patients with heterozygous mutation at any gene locus of UGT1A1*6 and UGT1A1*28. Logistic regression analysis showed that the presence or absence of vomiting (P=0.013) and mucositis (P=0.005) was significantly correlated with heterozygous mutation of UGT1A1*28, and the severity of vomiting (P<0.001) and neutropenia (P=0.021) were significantly correlated with heterozygous mutation of UGT1A1*6. In colorectal cancer, UGT1A1*6 was significantly correlated to diarrhea (P=0.005), and the other adverse reactions spectrum was similar to that of the whole patient cohort, and efficacy and prognosis were similar between patients with different genotypes and patients treated with reduced CPT-11 dosage or not. CONCLUSIONS In clinical use, heterozygous mutations of UGT1A1*6 and UGT1A1*28 are related to the risk and severity of vomiting, diarrhea, neutropenia and mucositis in patients with Pan-tumor and colorectal cancer post CPT-11 therpy. In colorectal cancer, UGT1A1*6 is significantly related to diarrhea post CPT-11 use, efficacy and prognosis is not affected by various genotypes or CPT-11 dosage reduction.
Camptothecin/therapeutic use* ; Glucuronosyltransferase/genetics* ; Humans ; Lung Neoplasms/drug therapy* ; Mutation ; Polymorphism, Genetic ; Retrospective Studies

Objective: To investigate the factors affecting the success of conversion therapy in patients with initially unresectable colorectal cancer liver metastases (CRLM) in order to provide evidence-based medical evidence for formulating individualized treatment strategies for patients. Methods: A retrospective case-control study was used in this study. Clinical data of 232 patients with initially unresectable CRLM receiving first-line systemic treatment in Sun Yat-sen University Cancer Center from January 2013 to January 2020 were collected, including 98 patients of successful conversion and 134 patients of failed conversion as control. Conversion therapy scheme: 38 patients received FOLFOXIRI regimen chemotherapy (irinotecan, oxaliplatin, calcium folinate and fluorouracil), 152 patients received FOLFOX regimen (oxaliplatin, calcium folinate and fluorouracil), 19 patients received FOLRIRI regimen (irinotecan, calcium folinate and fluorouracil), 23 patients received systemic chemotherapy combined with fluorouridine hepatic artery infusion chemotherapy; 168 patients received targeted therapy, including 68 of bevacizumab and 100 of cetuximab. Logistics analysis was used to compare the factors affecting the success of conversion therapy. The Kaplan-Meier method was used to calculate progression-free survival (PFS), and the Log-rank test was used for survival comparison. Results: Among 232 patients, 98 patients had successful conversions and 134 patients had failed conversions with a successful conversion rate of 42.2%, meanwhile 30 patients underwent simple hepatectomy and 68 underwent hepatectomy combined with intraoperative radiofrequency ablation. After first-line chemotherapy, 111 patients (47.8%) were partial remission, 57 patients (24.6%) were stable disease, and 64 patients (27.6%) were progression disease. During the median follow-up of 18.8 (1.0-87.9) months, 148 patients were dead or with tumor progression. The median PFS time of patients with successful conversion was longer than that of patients with failed conversion (31.0 months vs. 9.9 months, P<0.001). Univariate analysis found that the bilobar distribution of liver tumors (P=0.003), elevated baseline carcinoembryonic antigen (CEA) levels (P=0.024), tumor invasion of the portal vein (P=0.001), number of metastatic tumor>8 (P<0.001), non-FOLFOXIRI (P=0.005), and no targeted therapy (P=0.038) were high risk factors for the failed conversion therapy. The results of multivariate logistics analysis indicated that the number of metastatic tumor >8 (OR=2.422, 95%CI: 1.291-4.544, P=0.006), portal vein invasion (OR=2.727, 95%CI: 1.237-4.170, P=0.008) were the independent risk factors for failed conversion therapy, while FOLFOXIRI regimen (OR=0.300, 95%CI: 0.135-0.666, P=0.003) and targeted drugs (OR=0.411, 95%CI: 0.209-0.809, P=0.010) were independent protective factors for successful conversion therapy. Conclusions: The number of metastatic tumor and portal vein invasion are key factors that affect the outcomes of conversion therapy for initially unresectable CRLM. If a patient can tolerate chemotherapy, a combination program of three-drug and targeted therapy is preferred for the active conversion therapy.
Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Camptothecin/therapeutic use* ; Case-Control Studies ; Colorectal Neoplasms/drug therapy* ; Fluorouracil/therapeutic use* ; Humans ; Leucovorin/therapeutic use* ; Liver Neoplasms/drug therapy* ; Prognosis ; Retrospective Studies

As a newly emerged class of anticancer bioagents in the most precise and selectively targeted way, antibody-drug conjugate (ADC) combines the cancer-targeting abilities of monoclonal antibodies with the cytotoxicity potency of payload, delivering highly cytotoxic drug into tumors via 'targeted chemotherapy'. ADC has revolutionized the treatment landscape of human epidermal growth factor receptor 2 positive and triple negative subtypes in breast cancer. Three ADCs have been approved by U. S. Food and Drug Administration with breast cancer indications, including trastuzumab emtansine (T-DM1; also approved in China), trastuzumab deruxtecan (T-DXd, DS-8201) and sacituzumab govitecan (IMMU-132; also approved in China). Antibodies, cytotoxic drug, linker, and conjugation process are implicated in ADC profile, resulting in unique adverse drug reactions and toxicity heterogeneity within ADC class. For example, more attention should be paid to the management of thrombocytopenia, hepatotoxicity, and reductions in left ventricular ejection fraction (LVEF) in patients treated with trastuzumab emtansine; clinical physicians should pay attention to the risk of neutropenia, interstitial lung disease/pneumonitis, and reductions in LVEF when treated with trastuzumab deruxtecan; sacituzumab govitecan most frequently caused neutropenia, anemia and diarrhea requiring close monitor. ADC has generally favorable safety profiles, and dose modifications and/or symptomatic supporting treatment are effective in terms of toxicity management. This consensus aims at providing guidance for clinical oncologists of early detection, regular assessment, timely management and follow-up monitor of ADC-associated adverse reactions/events.
Ado-Trastuzumab Emtansine/therapeutic use* ; Antibodies, Monoclonal/therapeutic use* ; Antineoplastic Agents, Immunological/therapeutic use* ; Breast Neoplasms/therapy* ; Camptothecin/adverse effects* ; Consensus ; Cytotoxins/therapeutic use* ; Female ; Humans ; Immunoconjugates/therapeutic use* ; Neutropenia/etiology* ; Receptor, ErbB-2/metabolism* ; Trastuzumab/therapeutic use* ; Triple Negative Breast Neoplasms/therapy* ; Ventricular Function, Left

Colorectal cancer is the second most common malignant tumor in China. The FOLFOXIRI regimen, which combines 5-fluorouracil/leucovorin, oxaliplatin, and irinotecan, is a high-intensity and highly effective chemotherapy regimen. However, the original regimen is poorly tolerated in Chinese patients. In order to promote the standardized and rational application of FOLFOXIRI regimen by clinicians in China, "
Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Camptothecin/therapeutic use* ; China ; Colorectal Neoplasms/drug therapy* ; Consensus ; Fluorouracil/therapeutic use* ; Humans ; Irinotecan/therapeutic use* ; Leucovorin/therapeutic use* ; Organoplatinum Compounds/therapeutic use* ; Oxaliplatin ; Treatment Outcome

OBJECTIVETo evaluate the safety and preliminary efficacy of dose-modified regimen of 5-fluorouracil plus oxaliplatin and irinotecan (mFOLFOXIRI) for patients with advanced colorectal cancer (CRC).

METHODSData of 312 CRC patients confirmed by pathology receiving triplet drug alone or combined with target therapy between October 2012 and December 2016 at the Sixth Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. CRC patients who had previously completed adjuvant therapy (or neoadjuvant therapy) within 6 months or palliative chemotherapy were excluded, meanwhile those with poor general condition (ECOG score > 2) or grade 2 neuropathy and allergy to oxaliplatin were excluded as well. Regimen of mFOLFOXIRI: oxaliplatin 85 mg/m² dissolved in 5% glucose solution 500 ml by intravenous infusion for 2 h; irinotecan 150 to 165 mg/m² dissolved in 0.9% sodium chloride 250 ml by intravenous infusion for 90 min; following intravenous infusion of leucovorin 400 mg/m² for 2 h, day 1; 5-FU 2800 mg/m², 48-h continuous intravenous infusion; once every 2 weeks. Therapy could be combined with a targeted drug, bevacizumab 5 mg/kg every two weeks; cetuximab 500 mg/m² every two weeks. Side effect was graded using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE 4.0.3). The objective response rate was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) after administering at least four cycles of chemotherapy.

RESULTSThe median age was 52 years (range 16-73) in the whole group; 113 patients (36.2%) had locally advanced CRC, and 199 (63.8%) had metastatic CRC. Most patients (274/312, 87.8%) did not receive any treatment earlier. There were a total of 1651 chemotherapy cycles in the whole group, with a median of 6(1-19) cycles. Of these 1651 cycles, 124 cycles of chemotherapy(7.5%) were dose-adjusted; 176 cycles of chemotherapy(10.7%) were delayed for median 5(3-13) days; 124 cycles(7.5%) required dose decrease. The overall relative dose intensity was >90%; the specific drug dose intensity was 93.6%(2620 mg×m⁻²×d⁻¹) for fluorouracil, 97.8%(83 mg×m⁻²×d⁻¹) for oxaliplatin, and 94.2%(155 mg×m⁻²×d⁻¹) for irinotecan. Twenty-three patients (7 of intestinal perforation, 7 of intestinal obstruction, 1 of grade 4 hematologic toxicity, and 8 of grade 3 fatigue) refused subsequent chemotherapy due to intolerable toxicity. Main grade 3 or 4 adverse events in patients were neutropenia in 69 cases (22.1%), fatigue in 35 cases (11.2%), and anemia in 28 cases (8.9%). Twenty serious adverse events (6.4%) occurred, including 13 patients of febrile neutropenia (4.2%), 7 patients of intestinal perforation (2.2%, 4 patients in upper rectum, 2 in sigmoid colon, and 1 in transverse colon cancer), and 9 of them had subsequent sepsis (2.9%). All the patients with intestinal perforation underwent emergency operation. No treatment-related deaths occurred. In 199 patients with metastatic CRC, because 22 patients did not receive image evaluation, the preliminary efficacy of 177 patients was actually evaluated. A total of 113 objective response events were observed. The overall response rate was 63.8%(113/177), partial response rate was 61.6%(109/177), clinically complete response rate was 2.3%(4/177), stable disease was 29.9% (53/177), progressive disease was 6.2%(11/177), and the disease control rate was 93.8%(166/177). In 127 patients receiving triplet drug, objective response rate was 40.9% for those with less than four cycles and 81.1% for those with more than four cycles (P<0.001).

CONCLUSIONThe mFOLFOXIRI regimen with reduced dose can be safely used in advanced CRC and has achieved promising results in terms of short-term efficacy.

Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; administration & dosage ; therapeutic use ; Camptothecin ; administration & dosage ; analogs & derivatives ; Colorectal Neoplasms ; drug therapy ; Fluorouracil ; administration & dosage ; Humans ; Leucovorin ; administration & dosage ; Middle Aged ; Organoplatinum Compounds ; administration & dosage ; Retrospective Studies ; Treatment Outcome ; Young Adult

OBJECTIVETo analyze the relationship between primary tumor location and clinical response of chemotherapy in patients with metastatic colorectal cancer(mCRC).

METHODSClinical data of 721 mCRC patients who received first-line and second-line chemotherapy in Peking University Cancer Hospital between January 1996 and December 2011 were collected. All the patients were divided into 5 groups according to primary tumor location: ileocecum in 61 patients(8.5%), ascending colon or hepatic flexure in 126 patients (17.5%), transverse colon or splenic flexure in 26 patients (3.6%), descending or sigmoid colon in 172 patients (23.9%), rectum in 336 patients (46.6%). Outcomes of chemotherapy were evaluated by Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1), including complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). The overall response rate (ORR) was counted with the total number of patients divided by the number of CR+PR. Differences in first-line and second-line chemotherapy efficacy among different primary tumor sites in metastatic colorectal cancer were compared by using Chi-square test.

RESULTSOf the 571 patients receiving first-line chemotherapy, no one patient was classified as CR, while there were 190 as PR (33.3%), 277 as SD (48.5%) and 104 as PD (18.2%), with ORR 33.3% (190/571). The ORRs of patients with primary tumor located at ileocecum, ascending colon or hepatic flexure, transverse colon or splenic flexure, descending or sigmoid colon, rectum were 21.3% (10/47), 35.3% (36/102), 14.3% (3/21), 41.3% (57/138) and 31.9% (84/263), respectively, with statistically significant difference(P = 0.028). Difference of oxaliplatin-based first-line chemotherapy efficacy among different tumor sites was statistically significant(P = 0.009), while differences in irinotecan-based or single-agent 5-fluorouracil chemotherapy efficacy were not statistically significant (all P>0.05). In patients with primary tumor located at transverse colon or splenic flexure, irinotecan-based first-line chemotherapy had higher ORR than oxaliplatin-based or single-agent 5-fluorouracil chemotherapy, and the difference was statistically significant (P=0.042). There was no significant difference in the efficacy of different first-line chemotherapy regimens in patients with primary tumor located at other sites (all P>0.05). Of the 353 patients receiving second-line chemotherapy, no one patient was classified as CR, while there were 43 as PR (12.2%), 187 as SD (53.0%) and 123 as PD (34.8%), with ORR 12.2%(43/353). The ORRs of patients with primary tumor located at the ileocecum, the ascending colon or the hepatic flexure, the transverse colon or the splenic flexure, the descending or sigmoid colon, the rectum were 4.2%(1/24), 12.1%(8/66), 8.3%(1/12), 15.2%(12/79) and 12.3%(21/171) respectively, without statistically significant difference (P=0.686). Differences in second-line chemotherapy efficacy with the same regimen among different tumor sites were not statistically significant, and there were also no significant differences of efficacy of different second-line chemotherapy regimens in patients with the same tumor site (all P>0.05).

CONCLUSIONThere are differences in first-line chemotherapy efficacy among different primary tumor sites in metastatic colorectal cancer, while their second-line chemotherapy efficacy is equivalent.

Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Camptothecin ; analogs & derivatives ; Colon, Sigmoid ; Colon, Transverse ; Colorectal Neoplasms ; drug therapy ; Female ; Fluorouracil ; therapeutic use ; Humans ; Male ; Middle Aged ; Organoplatinum Compounds ; therapeutic use ; Rectum ; Retrospective Studies