Esophageal cancer is a disease with a specific geographical distribution, with a high incidence in Asia, Europe, and Africa[1]. Squamous cell carcinoma and adenocarcinoma are the most common pathological types[3]. Esophageal cancer accounts for about 50% of cancer patients throughout the world, with ESCC accounting for about 90% of esophageal cancer cases[3]. The pathogenic factors associated with esophageal cancer include alcohol and tobacco intake, HPV infection, preserved food, vitamin deficiency, and the consumption of high-temperature foods[1,4–7]. More than 80% of ESCC tumors are located in the middle and lower thoracic segments and are characterized by moderately and poorly differentiated squamous cell carcinoma[8]. The supraclavicular lymph node metastasis rate is about 15%, which is regarded as distant involvement, and the five-year survival rate for patients is about 24%[9]. Esophageal cancer is always locally advanced at the time of consultation due to atypical symptoms. Surgery, radiotherapy, and chemotherapy are the main treatment methods for locally advanced esophageal cancer[7]. The patient described here had middle and lower thoracic ESCC staged as T3N1M0 at the time of initial treatment using radical resection and adjuvant chemotherapy. The patient presented left supraclavicular lymph node and bone metastases after six years of follow-up. It has been found that the five-year survival rate of locally advanced esophageal cancer is about 15–40%[4], and long-term survivors subject to continuous exposure to genetic and behavioral risk factors can develop second primary cancers[10]. Analysis by the SEER database showed that the overall incidence of second primary cancer is about 2.4–17% while being as high as 30% in patients with esophageal cancer[10,11]. The case described here was potentially a metachronous second primary cancer with the diagnosis involving metastatic squamous cell carcinoma of the supraclavicular lymph nodes. The possible primary anatomical location could have been head-and-neck squamous cell carcinoma, cancer of the urinary system or skin, and even head-and-neck cancer of unknown primary origin. On the other hand, it has been confirmed that about 80% of patients with esophageal cancer develop metastasis at different times after the initial treatment[8,12]. Combined with related examinations, the present case was preferentially diagnosed as esophageal squamous cell carcinoma with metastasis of the left supraclavicular lymph node and bone. Chemotherapy or chemotherapy plus immunotherapy represent alternative options for metastatic ESCC with positive PD-L1 expression[7]. The combined use of docetaxel and cisplatin has been found to have a response rate of 25-34.2% in metastatic esophageal carcinoma after failure of PF first-line therapy[13–16]. Sintilimab is reported to be superior to chemotherapy alone for the second-line treatment of metastatic esophageal squamous cell carcinoma[17,18]. Multicenter randomized studies have demonstrated the benefit of immunotherapy in patients with squamous cell carcinoma with high PD-L1 expression[17–27], and the updated results are summarized in Table 1. Unfortunately, the patient described here did not achieve CR after chemotherapy and chemotherapy plus immunotherapy. Furthermore, the cancer progressed to refractory relapsed metastatic esophageal cancer after multiple lines of systemic therapy, while the optimum recommendation remained clinical trials or systemic treatment[3,7].
The ESWN01 study compared irinotecan plus S-1 with S-1 alone for the treatment of recurrent and metastatic esophageal cancer. It was found that while the combination chemotherapy was superior to monotherapy in terms of median OS and PFS, the overall prognosis remained poor[28]. Both the CHECKMATE648 and ATTRACTION3 studies demonstrated that Nivolumab plus chemotherapy was significantly better than chemotherapy alone in patients with recurrent and metastatic esophageal cancer, with a median OS of 10.5–15.4 months[22,25]. However, we observe that patients who received radiotherapy or resection were included in the above study. In the current study of a patient with lymph node recurrence and metastasis, treatment with chemotherapy and chemotherapy plus immunotherapy did not lead to CR, and even after adjustment of the treatment regimen, the cancer progressed, as seen in the development of Horner’s syndrome and brachial plexus injury-related symptoms and signs, seriously affecting the quality of life of the patient. The use of palliative local therapeutic interventions might be an optimal alternative treatment for symptom relief. It has been found concurrent chemoradiotherapy improved the prognosis of patients with metastatic esophageal cancer compared with radiotherapy alone[29–36]. In addition, the radiotherapy dose is a factor affecting the prognosis of patients with metastatic esophageal cancer[31]. It was confirmed that patients with metastatic esophageal cancer benefited from higher-dose (> 50.4 Gy) irradiation of primary foci[31,32,37]. In the current study, the patient was treated with ART-IMRT followed by Doppler ultrasound/CT dual-image guided three-dimensional implantation brachy radiotherapy due to the massive tumor burden and involvement of the vasculature and nerves. After aggressive multimodal radiotherapy, the control of the local tumors was satisfactory without obvious injury. Unexpectedly, the patient developed liver and lung metastases shortly afterward. It has been demonstrated that chemotherapy plus immunotherapy significantly improves the prognosis of patients with metastatic esophageal cancer[17,19,20,22,25,26,38,39]. The current patient received multi-line systemic therapy, including immunotherapy, before the concurrent radiochemotherapy, and did not achieve effective objective remission. In an analysis of the SEER database, the median OS of patients with and without liver-bone metastatic esophageal cancer was six months and nine months, respectively, and the patients were observed to benefit from local treatment[40]. In the current case, SBRT was performed on liver oligometastasis, resulting in reliable local control. The pulmonary metastases were not suitable for SIRT due to their multiplicity and small size, and alternative novel systemic therapy was considered. It has been found that the combination of the anti-angiogenic agent (Anlotinib) with immune checkpoint inhibitors had a synergistic effect and was recommended as an alternative for advanced esophageal cancer[39]. Furthermore, the first ESCORT study confirmed that Camrelizumab treatment led to 20% objective remission in patients with metastatic esophageal cancer[20]. The present patient achieved complete remission of all lung metastases after treatment with Anlotinib plus Camrelizumab, with the PFS for the liver and lung metastases maintained for 17 months and the left neck /supraclavicular metastases for 20 months. The long-term prognosis is still under follow-up. The outcome of this patient was better than any of the results in the studies described above, demonstrating the benefit of aggressive radiotherapy. Importantly, the patient showed excellent tolerance to the treatment with no adverse events. The optimal duration of maintenance therapy is unclear.
In the current study, aggressive multimodal radiotherapy resulted in an obvious improvement in both the quality of life and prognosis for a patient with metastatic disease, suggesting the value of aggressive radiotherapy combined maintenance systemic therapy as an alternative treatment for refractory recurrent metastatic esophageal cancer.
A limitation of this study was that treatment-related molecular detection was not conducted timeously, resulting in an absence of effective molecular markers for the guidance of treatment and prognosis prediction.