Table 1. Classification systems in use for LRRC.
| Study Group | Country | Time | Number of patients | Definitions |
|---|---|---|---|---|
| Mayo Clinic (27) | USA | 1995 | 224 | F0: no fixation |
| F1: fixation to 1 point | ||||
| F2: fixation to 2 points | ||||
| F3: fixation to more than 2 points | ||||
| Yamada (28) | Japan | 2001 | 60 | Localized: invasion to the adjacent pelvic organs or tissue |
| Sacral invasive: invasion to lower sacrum (S3, S4, S5), coccyx, periosteum | ||||
| Lateral invasive: invasion to sciatic nerve, greater sciatic foramen, lateral pelvic wall, upper sacrum (S1, S2) | ||||
| Memorial Sloan Kettering Cancer Center (29) | USA | 2003 | 55 | Axial: anastomotic, mesorectal, perirectal soft tissue, perineum |
| Anterior: genitourinary tract | ||||
| Posterior: sacrum and presacral fascia | ||||
| Lateral: soft tissues of the pelvic side wall and the lateral bony pelvis | ||||
| Leeds (30) | UK | 2005 | 64 | Central: pelvic organs or connective tissue without contact with or invasion into bone |
| Sacral: presacral space and abuts onto or invades into the sacrum | ||||
| Side wall: lateral pelvic side wall, including the greater sciatic foramen and sciatic nerve through to the piriformis and gluteal region | ||||
| Composite: sacral and side-wall recurrence combined | ||||
| Park (31) | Korea | 2009 | 62 | Central: anastomotic or perirectal soft tissue without fixed intrapelvic organ involvement |
| Anterior: bladder, prostate, seminal vesicles, and vagina Posterior: presacral area and/or involved sacral bone invasion | ||||
| Lateral: iliac vessels, pelvic ureter, lateral pelvic lymph node, and/or internal iliac lymph nodes | ||||
| Perineal: perineal skin | ||||
| Belli (32) | Italy | 2020 | 280 | S1: central/anterior |
| (I) Totally inside rectal wall | ||||
| (II) Pararectal without infiltration of regional organs | ||||
| (III) Pararectal with infiltration of regional organs (vagina, uterus, bladder, ureter) | ||||
| S2: posterior | ||||
| (I) Pararectal with sacral infiltration below the second sacral vertebra | ||||
| (II) Pararectal with sacral infiltration of the first or second sacral vertebra | ||||
| S3: lateral | ||||
| (I) Pararectal with infiltration of lateral pelvic compartment |
LRRC, locally recurrent rectal cancer.