title: p16INK4a methylation in serum as a follow-up marker for recurrence of colorectal cancer.
abstract: BACKGROUND
  p16(INK4a) methylation present in the tumors of colorectal cancer (CRC) patients can be detected in their serum using quantitative methylation-specific PCR (Q-MSP). To investigate the possibility that this technique could be applied to the monitoring for cancer recurrence in CRC patients, p16(INK4a) methylation in the serum of CRC patients during their follow-up period was evaluated.
  
  
  METHODS
  Using Q-MSP on serum samples from 21 CRC patients undergoing surgery for primary CRC, the p16INK4a methylation score (p16(INK4a) MS) was evaluated one day before surgery and during the follow-up period.
  
  
  RESULTS
  In the serum samples collected before primary resection, p16(INK4a) methylation was detected in 8 out of the 13 patients with same methylation in the tumor. The p16(INK4a) MS decreased within 2 weeks after surgery. Only two patients, who had the potential for recurrence, exhibited p16(INK4a) methylation in their serum. One month after surgery, in the patients with recurrence of tumor, a dramatic increase in p16(INK4a) MS was observed, while in the disease-free patients no methylation was seen continuously.
  
  
  CONCLUSIONS
  p16(INK4a) MS could sensitively reflect the recurrence status and may be useful for identifying the presence of recurrence during the follow-up of CRC patients.
authors: Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Aichi, Japan. goro@med.nagoya-u.ac.jp
authors: Goro
authors: G
authors: Nakayama
authors: Yasuhiro
authors: Y
authors: Kodera
authors: Norifumi
authors: N
authors: Ohashi
authors: Masahiko
authors: M
authors: Koike
authors: Michitaka
authors: M
authors: Fujiwara
authors: Akimasa
authors: A
authors: Nakao