preferred_name: Number of regional lymph nodes removed unknown, not stated; regional lymph nodes removed, NOS
preferred_name_lc: number of regional lymph nodes removed unknown, not stated; regional lymph nodes removed, nos
label: Number of regional lymph nodes removed unknown, not stated; regional lymph nodes removed, NOS
label_lc: number of regional lymph nodes removed unknown, not stated; regional lymph nodes removed, nos