MINISTRY OF EDUCATION AND TRAINING
MINISTRY OF HEALTH
HANOI MEDICAL UNIVERSITY
HOÀNG MINH ĐCỨ
RESEARCH ON SURGICAL OUTCOMES AND
RISK FACTORS OF RECURRENCE,
METASTASIS AFTER CURATIVE SURGERY
FOR COLORECTAL CANCER
Major: Gastrointestinal surgery
Code: 62720125
SUMMARY OF DOCTOR MEDICINE THESIS
Hanoi - 2019
THE THESIS IS COMPLETED AT:
HANOI MEDICAL UNIVERSITY
Scientific advisors: Assoc. Prof., Nguyen Thanh Long
First opponent: .........................................................
Second opponent: .....................................................
Third opponent: .......................................................
This thesis is defended at University Thesis Examination Council,
held at Hanoi Medical University
At … hour … minute on … … … 2019
The thesis may be read at following libraries:
- National Library of Vietnam;
- Library of Hanoi Medical University;
INTRODUCTION
Colorectal cancer is one of the most common malignancies;
according to the 2019 statistics World Health Organization each year
there are 1,8 million new cases and almost 861,000 deaths in 2018.
Despite recent significant medical advancement in diagnosis and
treatment of colorectal cancer in the recent years, recurrence and
metastasis after curative surgery for colorectal cancer have still been
serious challenges to clinical doctors. In the world, there have been a
number of researches on postoperative recurrence of colorectal cancer,
and these researches show that the rate of recurrence is about 20%-30%,
of which 60%-80% of recurrences occur within the first 2 years after
surgery. Colorectal cancer is classified as recurrent when new
malignant lesions are found, either local or metastatic, in patients
previously had curative surgery for colorectal cancer. Risks of
recurrence depend on various factors, of which the major factors are
disease stages, surgical features and postoperative adjuvant treatment.
In order to detect recurrent colorectal cancer, it is necessary to conduct
regular postoperative examinations with following clinical and
subclinical tests: Carcinoembryonic antigen (CEA) test, liver
ultrasound, chest X-ray, flexible colonoscopy - biopsy, CT scan, MRI
scan, PET - CT scans, etc. For treatment of recurrent colorectal cancer,
surgery is still the main treatment method, however whether a surgery is
possible depends on site of recurrence and degree of tumor growth.
Prognosis after surgery for recurrent colorectal cancer depends on
various factors, for example time of recurrence after surgery, disease
stage, and having adjuvant treatment or not. In the recent years, the
number of patients diagnosed with recurrent colorectal cancer and
underwent surgery has been increasing. Nevertheless, in our country
researches on this issue are still limited. Therefore, researching on
surgical outcomes and risk factors of recurrence and metastasis after
curative surgery for colorectal cancer is necessary and has scientific
implication for the purpose of generalizing features of recurrence,
treatment and outcomes of recurrence treatment as well as identifying
risk factors of recurrence after surgery for colorectal cancer. Objectives
of research:
1. Describing features of recurrence, metastasis after curative surgery
for colorectal cancer.
2. Assessing outcomes of surgery for recurrent and metastatic
colorectal cancer.
3. Analyzing a number of risk factors of recurrence, metastasis of
colorectal cancer.
CONTRIBUTIONS OF THE THESIS
1. Implications of the thesis
Results of this research shall help doctors of Gastrointestinal
surgery have more understandings of recurrence of colorectal cancer:
Site of recurrence, time of recurrence, metastasis, indication of surgery
for recurrent colorectal cancer and early and late outcomes of treatment.
Also, results of this research identify risk factors of recurrence, such as:
Age, disease stage, differentiation, histopathological type, features of
tumor growth by Bormann classification, and Petersen index (including
various factors: Vascular invasion, serosal invasion, invasion in
resection margin, necrotic tumors with perforation), which help
surgeons give advises on adjuvant treatment for patients having high
risks of recurrence.
This research has highly practical implications by providing
complete information about features of recurrence, indications and
methods of surgery and outcomes of treatment of recurrence after
curative surgery for colorectal cancer. Furthermore, this thesis provides
information about risk factors of recurrence, which can make treatment
after curative surgery for colorectal cancer be more effective.
This research has scientific implication with coherent layout and
appropriate method of data processing. Research data are processed by
modern medical algorithm being capable of properly solving the 3
objectives of research.
This thesis has creative, new and up-to-date features, and is the first
research that compares the 2 groups of patients with and without
recurrence for the purpose of identifying risk factors of recurrence in
Viet Nam.
2. Structure of thesis
The thesis comprises of 148 pages, with 87 tables, 5 charts, 2
diagrams and 20 images. The thesis has 4 chapters: Introduction (2
pages); Chapter 1 - Overview of literature (40 pages); Chapter 2 -
Subjects and methods of research (15 pages); Chapter 3 - Results of
research (36 pages); Chapter 4 - Discussion (50 pages) and Conclusion
(2 pages); the thesis has 255 references (18 in Vietnamese, and 255 in
English).
Chapter 1: OVERVIEW
1. Features of recurrence
Definition: Colorectal cancer is classified as recurrent when
new malignant lesions are found, either local or metastatic, in patients
previously had curative surgery for colorectal cancer, and at the same
time the current outcomes of anatomical pathology are similar to that of
the previous surgery.
Features of recurrence: Recurrence may be local (at
anastomosis, remaining colorectal section, surgical scar, trocar hole,
mesentery, or in the pelvis, etc.) or metastatic (in lung, liver, ovary,
peritoneum, etc.) Site of recurrence can be in any intra-abdominal
location, isolated or combined with metastasis. A recurrent tumor may
be local or invades other adjacent organs (invading vessels, kidney,
ureter, bladder, uterus, etc.). Rectal cancer has rate of local recurrence
(pelvis) higher than that of colon cancer, due to the characteristic of
invading surrounding organs in pelvic region via lymphatic system and
intravenous system. However, application of total mesorectal excision
(TME) and new chemoradiotherapy protocol has recently reduce rate of
recurrence of rectal cancer to 6%. The rate of anastomotic recurrence is
5 - 15% of the total number of patients, including invasive masses
outside of rectum and in front of sacrum. In contrast, colon cancer has