Editor’s note: From September 25 to 29, 2024, the 27th Annual National Clinical Oncology Conference and CSCO Academic Annual Meeting was successfully held in Xiamen. With the theme "Patient-Centered, Sharing the Future," the conference gathered significant research progress and developments from both domestic and international fields. Dr. Sanjun Cai from Fudan University Shanghai Cancer Center chaired the special session on perioperative treatment for colorectal cancer at this year’s conference. During the event, Oncology Frontier conducted an interview with Professor Cai to discuss recent advances and challenges in perioperative colorectal cancer treatment. Below is a summary of the interview to provide insight for the readers.

Oncology Frontier: As the session chair for perioperative diagnosis and treatment advancements in colorectal cancer at this year’s CSCO conference, could you provide an overview of the current status and latest progress in perioperative treatment for colorectal cancer?

Dr. Sanjun Cai: Colorectal cancer is a common malignant tumor with a high incidence rate. The primary mode of treatment is surgical, integrated with other therapies. Given that most colorectal cancer cases in China are advanced, the risk of recurrence or metastasis is quite high, especially in low rectal cancers, where postoperative recurrence is a significant concern. Therefore, perioperative treatment is crucial for improving surgical resection rates, enhancing prognosis, and extending the survival of colorectal cancer patients. In recent years, surgeons have broadened their focus beyond just the operation itself.

Perioperative treatment generally includes three aspects: preoperative neoadjuvant therapy, postoperative adjuvant therapy, and conversion therapy. Neoadjuvant therapy, administered before surgery, includes chemotherapy, chemoradiotherapy, and immunochemotherapy combinations. Initially, the goal of neoadjuvant therapy was to shrink the tumor to facilitate surgical resection. However, the current goals are broader. Recent studies indicate that neoadjuvant treatments like chemoradiotherapy can lead to a complete pathological response (pCR) in some tumors, allowing for smaller or even non-surgical treatments. This breakthrough signifies a new era in colorectal cancer treatment.

Postoperative adjuvant therapy targets high-risk recurrence factors to eliminate residual cancer cells, reducing the chances of recurrence or metastasis and thereby extending patient survival. Studies have shown that adjuvant chemotherapy is particularly beneficial for stage III (lymph node-positive) colorectal cancer patients, reducing the recurrence risk by about 30% and the mortality rate by 22% to 32%. It has become the standard treatment for such patients. Research in 2007 also confirmed the importance of adjuvant treatment in stage II (lymph node-negative) colorectal cancer patients, reducing disease recurrence risk by 22%, lowering mortality by 18%, and increasing the 5-year survival rate by 3% to 4%. Correct implementation of adjuvant therapy is, therefore, crucial for prolonging patient survival.

Lastly, conversion therapy plays a critical role. For patients with unresectable colorectal liver metastases, systemic treatment is a viable option. Effective systemic therapies can convert unresectable tumors into resectable ones, which is the aim of conversion therapy. Several studies have shown that patients who undergo conversion therapy and become eligible for local treatment experience significantly extended survival. In summary, the perioperative treatment system’s “three-pronged strategy” is vital for more thorough tumor removal and improved patient survival rates.

Oncology Frontier: In exploring perioperative treatment for colorectal cancer, what are the current academic focuses and challenges?

Dr. Sanjun Cai: Two main challenges exist in rectal cancer treatment: first, low surgical resection rates and satisfaction with resection; second, low rectal cancer patients often require stoma creation, which severely impacts their quality of life. To address these challenges, adjuvant radiotherapy began to be used after surgery in the late 1970s and early 1980s, initially focusing on local control. Attention then shifted to combining radiotherapy and chemotherapy, including concurrent chemoradiotherapy and addressing radiotherapy complications. In the 1980s, total mesorectal excision (TME) combined with adjuvant therapy became the standard treatment. In the early 21st century (around 2005), clinical trials showed that preoperative chemoradiotherapy should replace postoperative chemoradiotherapy as the standard treatment for locally advanced rectal cancer. A German study from 2004 revealed that preoperative chemoradiotherapy provides significant benefits in reducing local recurrence rates and improving anal preservation rates. Since then, neoadjuvant therapy has evolved continuously, improving tumor control and pCR rates.

One of the latest advances in neoadjuvant treatment is the combination of chemoradiotherapy and immunotherapy. The TORCH study, led by Fudan University Shanghai Cancer Center, showed that for patients with microsatellite-stable rectal cancer, a neoadjuvant combination of chemoradiotherapy and immunotherapy resulted in a complete response (CR) rate of 56%, a remarkable improvement. For the less common microsatellite instability (MSI) rectal cancer cases (about 5% to 10%), a study from New York achieved 100% clinical complete response (cCR), and this success persisted even as the number of cases expanded.

Looking to the future, rectal cancer treatment will likely divide into two categories based on microsatellite status: MSI and stable. For the former, monotherapy with immunotherapy could achieve close to a 100% cCR rate, with a pCR rate of 60% to 70%, offering patients the hope of avoiding or minimizing surgery and preserving organs. For the latter, the combination of chemoradiotherapy and immunotherapy can also achieve CR rates exceeding 50%, which is significant. These advancements not only improve treatment outcomes but also make significant strides in preserving patients’ quality of life.

Oncology Frontier: Could you share your story with CSCO? What led you to join the organization?

Dr. Sanjun Cai: CSCO is an organization focused on clinical oncology, dedicated to promoting advancements in the field. I joined CSCO in 2002. Over the years, I’ve witnessed the rapid growth of CSCO, from a small group of a few hundred people to a massive organization comprising tens of thousands of professionals. CSCO has been cultivating the soil of oncology education and research with unwavering commitment. Its contributions have significantly propelled the development of oncology in China and brought the voice of Chinese oncology to the global stage.

Many CSCO members have led research projects that have produced outstanding results. High-quality research papers frequently appear in prestigious international journals like the New England Journal of Medicine and the Journal of the American Medical Association (JAMA), focusing international attention on China’s remarkable achievements in oncology research.

What’s more exciting is the growing influence of Chinese research on the international stage, with increasing Chinese studies influencing and even rewriting international cancer treatment guidelines. This shift marks a historic leap in China’s standing and influence in global oncology research.

In conclusion, CSCO plays an irreplaceable role in promoting oncology education, research, and practice in China. The organization’s continuous expansion serves as an unstoppable force, pushing forward the country’s oncology healthcare and bringing hope and healing to countless cancer patients. I firmly believe that CSCO is not only an excellent organization but also a beacon of hope and a pioneer leading us into the future.

Dr. Sanjun Cai

Dr. Sanjun Cai serves as Director of the Colorectal Cancer Diagnosis and Treatment Center at Fudan University Shanghai Cancer Center and is the Chief Expert in Colorectal Cancer at the hospital’s multidisciplinary team. He holds key leadership roles in several oncology organizations and has been recognized with numerous prestigious awards, including the 2019 “National Famous Doctor-Excellence in Achievement Award” and the 2022 “Excellence in Innovation Award” in gastrointestinal oncology research.