Researchers at Osaka University find that mapping oesophageal tumours that remain after chemotherapy can predict long-term prognosis and direct personalised treatment plans.
Many newly-diagnosed cancer patients will always inevitably wonder, what are their chances of beating the disease? And more than often there is no clear answer, with survival rates differing widely depending on the cancer stage and available treatment options. However, post-operative testing that provides an accurate prediction of long-term treatment outcomes is the next best thing, allowing clinicians to plan further treatment or follow-up strategies and more accurately inform patients about their prognoses. Now in a recent study published in Annals of Surgery, a team led by researchers at Osaka University, Japan, examined tissue specimens from 120 individuals with oesophageal tumours following treatment, allowing them to both assess tumour characteristics and investigate how these related to long-term treatment outcomes.
Oesophageal tumours are the sixth most common cause of cancer-related death worldwide and, despite various treatment options, has a poor long-term prognosis.
Most locally-advanced oesophageal cancers are treated with neoadjuvant chemotherapy (NAC), which aims to increase the likelihood of successful curative surgery by decreasing the size of the tumour and eradicating systemic micro-metastases.
Tissue specimens are usually examined after surgery to assess how a tumour has responded to chemotherapy treatment. However, standard methods do not map the remaining tumour cells to the different layers of the oesophageal wall, and therefore provide an incomplete picture of treatment outcome.
The team hypothesised that there might be specific patterns of residual oesophageal tumours after NAC, and that they might have different clinical implications for patients.
Therefore, the researchers mapped the exact locations of residual tumours in the oesophageal wall of patients after NAC and assessed whether the location was associated with clinicopathological parameters including specific oncological outcomes.
Examining the tumour further
After NAC, they identified four tumour remnant patterns that are clearly different from those reported previously; the most common residual tumour pattern was a ‘shallow type.’ However, in approximately 40% of cases, tumour cells unexpectedly disappeared in the superficial (mucosal) layer of the oesophageal wall, indicating that it would be difficult to diagnose whether or not tumour cells completely disappeared after NAC based only on an endoscopic mucosal biopsy.
When the team examined associations between these patterns and disease factors, including prognosis, they found that pattern types 3 and 4 had higher risks of pleural dissemination and distant metastases than types 1 or 2. These results shows that patients displaying patterns 3 or 4 should have more regular follow-up appointments than those with pattern types 1 or 2. Interestingly, survival was similar among the four groups.
According to the research authors, by determining the oesophageal tumour remnant pattern from specimens and post-operative image examination, a personalised treatment plan for each patient can be developed. This customised approach is expected to significantly improve oesophageal cancer treatment outcomes.